Before going any further, here’s the main thing parents should know about swimming lessons: all children should have them.

Every year, over 4,500 people die from drowning in the United States — and, in fact, drowning is the leading cause of death for children ages 1 to 4. Swimming lessons can’t prevent all of those deaths, but they can prevent a lot of them. A child doesn’t need to be able to swim butterfly or do flip turns, but the ability to get back to the surface, float, tread water, and swim to where they can stand or grab onto something can save a life.

10 things parents should know about swimming lessons

As you think about swimming lessons, it’s important to know:

1. Children don’t really have the cognitive skills to learn to swim until they are around 4 years old. They need to be able to listen, follow directions, and retain what they’ve learned, and that’s usually around 4 years old, with some kids being ready a little earlier.

2. That said, swim lessons between 1 and 4 years old can be useful. Not only are some kids simply ready earlier, younger children can learn some skills that can be useful if they fall into the water, like getting back to the side of a pool.

3. The pool or beach where children learn must be safe. This sounds obvious, but safety isn’t something you can assume; you need to check it out for yourself. The area should be clean and well maintained. There should be lifeguards that aren’t involved in teaching (since teachers can’t be looking at everyone at all times). There should be something that marks off areas of deeper water, and something to prevent children from getting into those deeper areas. There should be lifesaving and first aid equipment handy, and posted safety rules.

4. The teachers should be trained. Again, this sounds obvious — but it’s not always the case. Parents should ask about how teachers are trained and evaluated, and whether it’s under the guidelines of an agency such as the Red Cross or the YMCA.

5. The ratio of kids to teachers should be appropriate. Preferably, it should be as low as possible, especially for young children and new swimmers. In those cases, the teacher should be able to have all children within arm’s reach and be able to watch the whole group. As children gain skills the group can get a bit bigger, but there should never be more than the teacher can safely supervise.

6. There should be a curriculum and a progression — and children should be placed based on their ability. In general, swim lessons progress from getting used to the water all the way to becoming proficient at different strokes. There should be a clear way that children are assessed, and a clear plan for moving them ahead in their skills.

7. Parents should be able to watch for at least some portion. You should be able to see for yourself what is going on in the class. It’s not always useful or helpful for parents to be right there the whole time, as it can be distracting for children, but you should be able to watch at least the beginning and end of a lesson. Many pools have an observation window or deck.

8. Flotation devices should be used thoughtfully. There is a lot of debate about the use of “bubbles” or other flotation devices to help children learn to swim. They can be very helpful with keeping children safe at the beginning, and helping them learn proper positioning and stroke mechanics instead of swimming frantically to stay afloat, but if they are used, the lessons should be designed to gradually decrease any reliance on them.

9. Being scared of the water isn’t a reason not to take, or to quit, swimming lessons. It’s common and normal to be afraid of the water, and some children are more afraid than others. While you don’t want to force a child to do something they are terrified of doing, giving up isn’t a good idea either. Start more gradually, with lots of positive reinforcement. The swim teacher should be willing to help.

10. Just because a child can swim doesn’t mean he can’t drown. Children can get tired, hurt, trapped, snagged, or disoriented. Even strong swimmers can get into trouble. While swimming lessons help save lives, children should always, always be supervised around water, and should wear life jackets for boating and other water sports.

The Centers for Disease Control and Prevention website has helpful information on preventing drowning. The American Red Cross offers an online water safety course for caregivers and parents and water safety videos for children. Many public pools and organizations like Boys & Girls Clubs and the YMCA offer swimming classes for all ages.

About the Author

Claire McCarthy, MD, Senior Faculty Editor, Harvard Health Publishing

Claire McCarthy, MD, is a primary care pediatrician at Boston Children’s Hospital, and an assistant professor of pediatrics at Harvard Medical School. In addition to being a senior faculty editor for Harvard Health Publishing, Dr. McCarthy … See Full Bio View all posts by Claire McCarthy, MD

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing

Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD

Pop quiz: what is Salmonella? If you’ve ever had a run-in with this bacteria, you know it can cause a food-borne illness called salmonellosis, a form of food poisoning. But you may not know that Salmonella bacteria sicken an estimated 1.35 million people and hospitalize 26,500 every year in the United States. What’s more, it kills more total people than any other type of food poisoning.

And Salmonella bacteria can be sneaky — not only by triggering unusual complications, but infecting people in startling ways, says Dr. Elizabeth Hohmann, an infectious disease specialist at Massachusetts General Hospital. One patient she treated showed up with an abdominal aortic aneurysm — a dangerous bulge in the lower section of the body’s largest artery — that looked infected. Testing revealed a culprit some would find surprising: Salmonella.

“It’s just an interesting organism and it can be kind of scary,” she says.

How do people get infected by Salmonella?

Many of the foods Salmonella bacteria lurk in are raw or undercooked. Breaded raw chicken products like nuggets and chicken Kiev are one way it may reach your table. But a variety of foods have been implicated — including organic basil, cantaloupes, ground beef, nut butters, raw cookie dough, eggs, raw or unpasteurized milk, and flour.

Even small pets such as turtles and frogs, along with dog food, have contributed to Salmonella outbreaks in recent years.

You can also become infected by handling contaminated food and spreading the bacteria from your hands to your mouth. Additionally, you can spread it to others on your hands or even on your clothes without becoming sick yourself.

“It’s a bug that’s carried in stool and animal feces and is also present in the environment,” Dr. Hohmann says. “So it can set up shop in lots of different inanimate objects, soils, and machinery, especially in moist environments.”

What symptoms can Salmonella cause?

Most of the time, Salmonella infection leads to gastroenteritis, usually causing just an upset stomach, abdominal cramps, and diarrhea. These symptoms can start as soon as six hours after ingesting the bacteria. Typically, symptoms resolve on their own within two to three days.

Some people have such mild symptoms they’re barely noticeable. “The classic case might be a college student who eats a burrito from a sketchy place, gets sick for a couple of days, gets better, and doesn’t think anything of it,” says Dr. Hohmann.

Sometimes symptoms are more serious, such as severe abdominal cramping and bloody diarrhea, or unexplained high fever and marked fatigue. These symptoms require a call to your doctor.

How is salmonellosis treated?

Most people will get better on their own without any medicines. Replacing lost fluids by sipping water or electrolyte drinks to avoid dehydration will help.

Call a doctor if you have

• diarrhea and a fever higher than 102° F
• diarrhea that doesn’t improve after three days
• bloody stools
• vomiting so severe it prevents you from keeping liquids down.

Treating the infection with medicine comes with an annoying paradox, Dr. Hohmann says. If doctors decide to prescribe antibiotics, the person taking the medicine may shed the organism for longer than if they were never treated. “Then that person may have the opportunity — either through poor personal hygiene, sex, or working as a food worker — to spread it to others,” she explains. “It’s challenging.”

What complications can Salmonella lead to?

Some people get sicker with salmonellosis than others, with seemingly no rhyme or reason. But certain folks are especially vulnerable to serious infection, including:

• adults 65 and older
• pregnant women
• children under 5
• people whose immune systems are weakened by diseases (such as cancer) or treatments (such as immunosuppressing drugs).

A small percentage of those infected can have Salmonella in their blood, which can spread the infection to other parts of the body such as the urinary tract, bones, joints, or central nervous system (brain and spinal fluid).

And, like Dr. Hohmann’s patient with the abdominal aortic aneurysm, on rare occasions Salmonella can lead to unusual blood vessel complications in people who already have atherosclerosis, blockage of the arteries caused by plaque buildup.

“It’s not that common,” she says. “Many physicians are aware of it, so they take special care if Salmonella is found in a person with vascular disease.”

What steps can you take to avoid Salmonella?

While new USDA rules that take effect in 2025 may help fuel recalls of certain foods, we all can take steps to avoid the food poisoning, illness, and hospitalizations that Salmonella exposure can cause.

Dr. Hohmann and the CDC suggest these strategies:

• Using hot water and soap, wash cutting boards or plates on which you cut into raw foods — including vegetables and fruit — before using those surfaces for other purposes. If possible, use separate cutting boards for produce, meat, and fish.
• Refrigerate or freeze foods that are perishable, prepared, or left over within two hours to thwart salmonella growth.
• Always wash hands well with soap and water before preparing food and after contact with animals, using the toilet, or changing diapers.
• If you have a sick pet, take extra care handling its feces and wash your hands thoroughly afterward.

Take additional steps to help more vulnerable people stay healthy:

• Don’t let young children touch high-risk animals, such as turtles, frogs, chickens, or ducks. “And if you’re taking young children to a petting zoo, they should not be petting animals unless you can disinfect their hands immediately afterward,” she says.
• Older adults and those with compromised immune systems should take extra care to wash and cook foods thoroughly.
• People who have had a transplant (such as a kidney transplant) should not keep reptiles or amphibians as pets.

“You hate to make people paranoid, so that we’re washing our lettuce leaves with soap, but it’s worth thinking about these things, particularly if you have people in your household who are susceptible — which is an increasing number of people,” Dr. Hohmann says.

About the Author

Maureen Salamon, Executive Editor, Harvard Women's Health Watch

Maureen Salamon is executive editor of Harvard Women’s Health Watch. She began her career as a newspaper reporter and later covered health and medicine for a wide variety of websites, magazines, and hospitals. Her work has … See Full Bio View all posts by Maureen Salamon

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing

Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD

On the Gulf Coast of Florida where I live, the telltale sign of summer is not an influx of beachcombers, afternoon storms that arrive exactly at 2 p.m., or the first hurricane warning, but the appearance of hundreds of paddleboarders dotting the inlet waters.

From afar, paddleboarding looks almost spiritual — people standing on nearly invisible boards and gliding across the surface as if walking on water.

But this popular water sport offers a serious workout, just as kayaking and canoeing do. While floating along and casually dipping a paddle in the water may look effortless, much goes on beneath the surface, so to speak.

As warm weather beckons and paddle season arrives, it pays to get key muscles in shape before heading out on the water.

Tuning up muscles: Focus on core, back, arms, and shoulders

“Paddling a kayak, canoe, or paddleboard relies on muscles that we likely haven’t used much during winter,” says Kathleen Salas, a physical therapist with Spaulding Adaptive Sports Centers at Harvard-affiliated Spaulding Rehabilitation Network. “Even if you regularly weight train, the continuous and repetitive motions involved in paddling require endurance and control of specific muscles that need to be properly stretched and strengthened.”

While paddling can be a whole-body effort (even your legs contribute), three areas do the most work and thus need the most conditioning: the core, back, and arms and shoulders.

• Core. Your core comprises several muscles, but the main ones for paddling include the rectus abdominis (that famed “six-pack”) and the obliques, located on the side and front of your abdomen. The core acts as the epicenter around which every movement revolves — from twisting to bending to stabilizing your trunk to generate power.
• Back: Paddling engages most of the back muscles, but the ones that carry the most load are the latissimus dorsi muscles, also known as the lats, and the erector spinae. The lats are the large V-shaped muscles that connect your arms to your vertebral column. They help protect and stabilize your spine while providing shoulder and back strength. The erector spinae, a group of muscles that runs the length of the spine on the left and right, helps with rotation.
• Arms and shoulders: Every paddle stroke engages the muscles in your arms (biceps) and the top of your shoulder (deltoids).

Many exercises specifically target these muscles, but here are three that can work multiple paddling muscles in one move. Add them to your workouts to help you get ready for paddling season. If you haven’t done these exercises before, try the first two without weights until you can do the movement smoothly and with good form.

Three great exercises to prep for paddling

Wood chop

Muscles worked: Deltoids, obliques, rectus abdominis, erector spinae
Reps: 8–12 on each side
Sets: 1–3
Rest: 30–90 seconds between sets

Starting position: Stand with your feet about shoulder-width apart and hold a dumbbell with both hands. Hinge forward at your hips and bend your knees to sit back into a slight squat. Rotate your torso to the right and extend your arms to hold the dumbbell on the outside of your right knee.

Movement: Straighten your legs to stand up as you rotate your torso to the left and raise the weight diagonally across your body and up to the left, above your shoulder, while keeping your arms extended. In a chopping motion, slowly bring the dumbbell down and across your body toward the outside of your right knee. This is one rep. Finish all reps, then repeat on the other side. This completes one set.

Tips and techniques:

• Keep your spine neutral and your shoulders down and back
• Reach only as far as is comfortable.
• Keep your knees no farther forward than your toes when you squat.

Make it easier: Do the exercise without a dumbbell.

Make it harder: Use a heavier dumbbell.

Bent-over row

Muscles worked: Latissimus dorsi, deltoids, biceps
Reps: 8–12
Sets: 1–3
Rest: 30–90 seconds between sets

Starting position: Stand with a weight in your left hand and a bench or sturdy chair on your right side. Place your right hand and knee on the bench or chair seat. Let your left arm hang directly under your left shoulder, fully extended toward the floor. Your spine should be neutral, and your shoulders and hips squared.

Movement: Squeeze your shoulder blades together, then bend your elbow to slowly lift the weight toward your ribs. Return to the starting position. Finish all reps, then repeat with the opposite arm. This completes one set.

Tips and techniques:

• Keep your shoulders squared throughout.
• Keep your elbow close to your side as you lift the weight.
• Keep your head in line with your spine.

Make it easier: Use a lighter weight.

Make it harder: Use a heavier weight.

Superman

Muscles worked: Deltoids, latissimus dorsi, erector spinae
Reps: 8–12
Sets: 1–3
Rest: 30–90 seconds between sets

Starting position: Lie face down on the floor with your arms extended, palms down, and legs extended.

Movement: Simultaneously lift your arms, head, chest, and legs off the floor as high as is comfortable. Hold. Return to the starting position.

Tips and techniques:

• Tighten your buttocks before lifting.
• Don’t look up.
• Keep your shoulders down, away from your ears.

Make it easier: Lift your right arm and left leg while keeping the opposite arm and leg on the floor. Switch sides with each rep.

Make it harder: Hold in the “up” position for three to five seconds before lowering.

About the Author

Matthew Solan, Executive Editor, Harvard Men's Health Watch

Matthew Solan is the executive editor of Harvard Men’s Health Watch. He previously served as executive editor for UCLA Health’s Healthy Years and as a contributor to Duke Medicine’s Health News and Weill Cornell Medical College’s … See Full Bio View all posts by Matthew Solan

About the Reviewer

Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing

Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD

Are you finding yourself with itchy, irritated skin that you can’t stop scratching? Or have you wondered why your child’s eczema is suddenly worse and so hard to control? Mounting evidence suggests that wildfires, which are increasing in intensity and frequency, contribute to skin problems, including eczema flares.

What is eczema?

Eczema is a common chronic skin condition that affects about one in 10 people in the US. Its hallmarks are inflamed and dry, itchy patches of skin.

Atopic dermatitis is the most common type of eczema. It can run in families, often beginning in childhood. Typically, in the northern hemisphere, it grows worse during the winter season when the weather is cold and drying. Now some experts are seeing that pattern change. At Massachusetts General Hospital, for example, one dermatologist noted an unusual spike last summer in patients with flare-ups of eczema.

Why is eczema getting worse during summer?

In 2023, Canada experienced more than 6,000 wildfires that burned over 16 million hectares of land — an area larger than the entire state of Georgia. While far away from the devastation, the smoke reached across the US and more than 2,000 miles to Europe. Poor air quality from these distant wildfires caused eye and throat irritation and difficulty breathing.

In Boston, Dr. Arianne Shadi Kourosh, a dermatologist at Massachusetts General Hospital, also began to notice skin symptoms. Normally the dermatology clinics would see fewer than 20 people during a summer month for eczema, including atopic dermatitis. Suddenly that jumped to 160.

Looking back at summer month records from the last four years, her research showed that the number of visits for these skin complaints tracked with the severity of air pollution. These findings are consistent with other research noting an uptick in eczema flares and psoriasis flares associated with wildfire pollution. But why?

Researchers theorize that airborne pollutants might set off a cascade of effects within the body by activating an oxidative stress pathway. This damages the skin barrier and prompts an inflammatory response. This cascade also may play a role in the development of eczema.

What can you do to protect your skin?

Air pollutants in wildfire smoke may harm multiple organs — not just your heart and lungs, but also our skin, it seems. So, when outdoor air quality is bad due to wildfires, limiting your exposure can help reduce health risks. While we can say the same for industrial air pollution, wildfire pollution is likely worse due to its additional toxic particles.

• Seek help if you’re itching. Check with a dermatologist or your health team if you think wildfire smoke or other forms of air pollution might be affecting your skin.
• Check local air quality.AirNow.gov shares local, real-time air quality information and activity guidance. When recommended, stay indoors if possible. Shut doors, windows, and any outdoor air intake vents.
• Protect your skin. When you’re outdoors, wear a mineral-based sunscreen containing zinc or titanium. While most other sunscreens work through a chemical reaction to absorb the ultraviolet (UV) rays that damage skin, zinc and titanium sunscreens help by forming a barrier over skin that reflects off UV rays. The barrier also reduces the amount of pollutant particles getting to the skin to set off the inflammatory cascade. Wearing sunscreen protects against skin cancer, as well.
• Wash up. After coming back inside, cleansing your skin and applying a hypoallergenic moisturizer will help keep it healthy. If you do have eczema, choose cleansers and moisturizing products recommended by your dermatologist or health care provider.

About the Author

Wynne Armand, MD, Contributor

Dr. Wynne Armand is a physician at Massachusetts General Hospital (MGH), where she provides primary care; an assistant professor in medicine at Harvard Medical School; and associate director of the MGH Center for the Environment and … See Full Bio View all posts by Wynne Armand, MD

Do you ever read the notes written by your doctor or health practitioner during a medical visit? If not, you might want to check them out. Usually, these medical notes are full of helpful insights about your health and reminders of recommendations discussed. And there’s medicalese, of course: hard-to-pronounce illnesses, medications, and technical terms.

But you may be surprised to see incorrect information or unexpected language, tone, or even innuendo. Was your past medical history really that “unremarkable”? Did you actually “deny” drinking alcohol? Did the note describe you as “unreliable”?

Here’s how to decipher unfamiliar lingo, understand some surprising descriptions, and flag any errors you find.

What’s in a medical note?

A standard medical note has several sections. These include

• a description of current symptoms
• past medical problems
• a list of medications taken
• family medical history
• social habits such as smoking, drinking alcohol, or drug use
• details of the physical examination
• test results
• a discussion of the big picture, along with recommendations for further evaluation or treatment.

Notes tend to be more complete for a new patient or annual exam. Follow-up notes may not cover all of these points.

What’s potentially confusing about medical notes?

Most medical notes aren’t written using plain language because they aren’t intended primarily for a nonmedical audience. So it’s common to run across:

• Medical jargon: You had an upset stomach and a fever. Doctors may say “dyspepsia” (upset stomach) and “febrile” (fever).
• Complicated disease names: Ever heard of “multicentric reticulohistiocytosis” or “progressive multifocal leukoencephalopathy?” These are just two of thousands of examples.
• Use of common language in uncommon ways: For example, your medical history might be called “unremarkable” and test results called "within normal limits” rather than “normal.”
• Abbreviations: You might see “VSS” and “RRR,” meaning “vital signs stable” with a pulse that has a “regular rate and rhythm.”

If you’re having trouble deciphering a note or understanding your health issues, tests, and recommendations, check in with your doctor’s office for clarifications. The more you understand about your health and your options for care, the better.

What if a medical note is incorrect?

Minor errors in medical notes are not rare: maybe you had your tonsils removed 30 years ago, not 10 years ago. But there can be more important errors: stating that arthritis in your left knee is severe when it’s actually the right knee that’s severe could lead to having x-rays (or even surgery!) on the wrong side. And not properly recording a family history of cancer or heart disease could mean missing out on timely screening tests or preventive treatments.

In an era of ever-increasing time pressure, use of voice recognition software, electronic record templates, drop-down menus, and ability to copy and paste text, it’s easier than ever for health care providers to make (and perpetuate) errors in the medical record.

If you do see an important error that could affect your health, ask your provider to amend it.

What if the language in a medical note seems offensive?

Numerous studies have highlighted the problem of stigmatizing language in medical notes that can leave people feeling judged or offended. Negative attitudes can affect the quality of our health care and willingness to seek care, and can also widen health disparities. One study linked stigmatizing language to higher rates of medical errors. Of note, this study found higher rates of stigmatizing language and medical error among black patients.

Examples include:

• Depersonalization: A note might describe a patient as “a drug abusing addict” rather than a person struggling with drug addiction.
• Insulting or inappropriate descriptors: Notes might contain subjective descriptions that paint the patient in an unflattering light without providing context. For example, the note might say “the patient is unkempt and is drug-seeking” rather than “the patient is experiencing homelessness and has severe, chronic pain.” If a person’s recall of medical events from the past is hazy, they may be called “unreliable.”
• Dismissiveness: A medical note may suggest a symptom is not real or is exaggerated, rather than taking the complaint seriously.
• An untrusting tone: Language such as “she claims she never drinks” or “he denies alcohol use” may suggest mistrust by the physician.

Why might this happen, anyway?

How does such language make its way into medical notes? (To be clear, these possible explanations are not justifications.)

• Tradition and training: Medical trainees, like other learners, tend to follow the lead of their mentors. So if stigmatizing language is used by an instructor, trainees may do the same.
• Time pressure: With medical documentation (as in most everything else), mistakes are more common if you’re rushing.
• Bias: Like everyone else, doctors have biases, including ones they aren’t aware of. How we are taught to think about people — by family, by society — can spill over into every area of life, including work.
• Frustration: Doctors may feel frustrated by patients who don’t follow their recommendations. That frustration can be reflected in their medical notes. For example, a note may say, “As expected, the patient’s blood sugar is high; he is still not checking his blood sugar or following the diet recommended by his nutritionist.”

If the language in a note is confusing or bothersome, ask about it. The Open Notes movement and federal legislation have given most of us much better access to our medical records. This has worthy goals — greater transparency and better communication with people about their medical care — and unintended consequences.

Is changing language in notes that health practitioners once shared mainly with each other a positive consequence? Mostly. Yet some doctors worry that notes will become less specific, accurate, or useful since they may leave out information that might upset a patient.

The bottom line

I encourage you to read your health providers’ notes about your care. If there is a substantial error or something you find confusing or objectionable, ask about it. By the way, a signed medical note cannot usually be revised. However, your doctor can make clarifications or correct mistakes in an addendum at the end of the note.

As more and more patients read their medical notes, it’s likely that health providers will be more conscientious about the language they use. So, wide access to medical notes may improve not only people’s understanding of their health, but also the quality of notes over time.

It's worth remembering that the medical note is not the most important thing that happens during a visit to your doctor. A great note isn’t the same as great care, and vice versa. Still, your medical notes can be a valuable source of health information that differs from all others, including trusted health sites and social media: they’re written by your doctor and they’re all about you.

About the Author

Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD

It’s undeniable: modern medicine offers ever-expanding ways to heal and prevent disease. But it’s also true that health care can cause harm. One analysis found that about 6% of health care encounters caused preventable harm, leading to thousands of deaths each year. And it’s not just errors that cause trouble. Highly skilled health care providers can cause harm even when they do everything right.

So, how can you reduce your chances of being harmed? Understanding what you can do to lessen the possibility of harm and what’s beyond your control are good first steps.

Whatever happened to “first do no harm”?

Fortunately, it remains a central tenet of medical care. Yet our health care system is complex and fragmented. Each year new medications are added to an ever-growing list, and people live longer with more chronic medical conditions than happened in the past. So in one sense, the successes of modern medical care may contribute to the high rate of health care–related harm.

These harms are often due to our complicated system of health care rather than one individual’s mistake. Harm due to substandard or negligent care is known as medical malpractice. Both health care providers and health care systems have important roles to play in preventing harm to patients.

Are there harms that cannot be prevented?

An enormous volume of scientific research teaches the best ways to diagnose, treat, and prevent disease. Yet people can react to treatments in completely unpredictable ways.

For example, a common and standard antibiotic treatment (think penicillin) can cause anaphylaxis, a life-threatening allergic reaction. Fortunately this is rare, but unless you or your doctor know to avoid it due to past side effects, there’s always a small chance of a severe reaction.

Often less dramatic — yet also unpreventable — harms are:

• Medication side effects. Every medicine comes with potential side effects, such as nausea, sleepiness, or rash.
• Misdiagnosis. Because no one has perfect diagnostic skills, even the most skillful health care provider can be wrong. This can result in unnecessary or delayed treatment.
• Inaccurate test results. Just as no health care provider is perfect, no test is either. False-positive results (indicating an abnormality when none is present) and false-negative results (normal results when disease is present) are common in medical practice. These results can lead to unnecessary treatment or false reassurance.

Which harms can be prevented?

Preventable harms can be dramatically reduced. They’re often due to mistakes that can be caught and corrected. Frequently, it takes a combination of things to go wrong for harm to occur.

The “Swiss cheese model” is often applied here: imagine you’re a fly trying to travel through several chunks of Swiss cheese. (I know it’s an odd scenario, but stick with me here.) It’s impossible to fly through the cheese unless the holes line up just so.

Frequently in health care, several factors must line up for an error to sneak through — for example, giving a hospitalized patient a medication to which they are allergic. For that to happen, the wrong drug has to get past the prescribing doctor, the computerized ordering system, the hospital pharmacist, the nurse giving the medication, and the patient. That’s a lot of layers, so most often an error like this will be caught.

What can you do to avoid preventable harms?

Where do you fit in? In these three scenarios, here’s what you can do to avoid preventable harms.

The problem: Taking medicines you no longer need or more medicines than necessary.

It might not seem like a big deal to keep taking a medicine if it isn’t causing any problems. But all medicines can cause side effects that you’d do better to avoid if you can safely stop taking it or reduce the dose. Plus, harmful interactions can occur if another medicine is added to your list.

What you can do: Make sure you know why you need to take each of your medicines. Ask the providers who prescribe each medicine if it is still necessary to take it or if the dose can be safely reduced. Reducing a dose may reduce the risk of side effects and the likelihood of a harmful interaction.

The problem: Taking the wrong medicine or the wrong dose.

What you can do: At your doctors’ visits, take notes or bring a friend or family member to help you remember medicine instructions. Ask whether you can record the medication instructions your doctor gives you. Take a photo of the instructions you’re given in case you lose the written version. Double-check details of your medicine list with your pharmacist. And ask questions if you’re unsure about the medicines recommended to you.

The problem: Wrong site surgery.

Despite efforts to make this a “never error,” surgery on the wrong part of the body still happens.

What you can do: Make sure you and your surgeon agree on what part of your body and which side requires surgery. Most surgeons now mark the site with a special pen before surgery and ask you to confirm the site by adding your initials. (The ink doesn’t come off easily with skin cleaners applied prior to surgery).

Some of these tips require time or resources that aren’t available to everyone: you might not be able to bring another person with you to medical visits or have a recording device. But asking questions — and getting answers you understand — should be routine.

Where does malpractice fit in?

When the topic of health care–related harm comes up, malpractice may be the first thing you think about. Yet, the approximately 10,000 malpractice payments made each year in the US likely represent only a small portion of all harm related to health care.

There are several reasons for this, including:

• Even when negligent or substandard care occurs, it doesn’t always cause major or long-lasting harm that leads to a malpractice claim.
• Many people who could file malpractice suits elect not to, or may not even realize that they’ve experienced negligent care. Past studies suggest that less than 5% of people experiencing harm related to medical care file malpractice claims.
• Increasingly, health care providers and health care systems accept responsibility for preventable harm occurring on their watch, and offer compensation rather than waiting for a legal claim to be filed.

The bottom line

It’s an unfortunate reality that some harms due to health care are inevitable. But there are steps you can take to avoid preventable harm and lessen the chances that the person harmed is you.

About the Author

Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD

You’ve probably heard the news: Cicadas are coming. Or — wait — they’re already here.

And are they ever! Due to an unusual overlap of the lifecycles of two types (or broods) of cicadas, trillions of cicadas are expected to emerge in the US by the end of June, especially in the Midwest.

If you’d like to see where they’ve already arrived, track them here. And if you’re wondering if this cicada-palooza could help with grocery bills, read on to decide for yourself how appealing and how safe snacking on cicadas is for you. The pros and cons could change your outlook on the impending swarm.

What to know about cicadas

Don’t worry, cicadas are largely harmless to humans. In fact, their appearance is welcome in places where people routinely snack on them as a low-cost source of calories and protein.

Estimates suggest up to two billion people regularly eat insects, especially in South and Central America, Asia, Africa, Australia, and New Zealand. Cicadas, when available, are among the most popular. And if you thought no one in the US eats cicadas, check out this video from a May 2024 baseball game.

Are you tempted to eat cicadas?

For plenty of people, cicadas aren’t the food of choice. Some people can’t get past the idea of eating insects as food. That’s understandable: after all, the culture in which we are raised has a powerful influence on what we consider acceptable in our diets. Something some Americans might find off-putting (such as eating snakes) is common in China and Southeast Asia. Meanwhile, people outside the US find aspects of the typical Western diet unappealing (such as root beer, peanut butter and jelly, and processed cheese).

But some people shouldn’t eat cicadas because it could be dangerous for them.

Why you should — or shouldn’t — eat cicadas

Eating cicadas is common in many parts of the world because they are

• nutritious: cicadas are low in fat and high in protein, including multiple essential amino acids
• inexpensive or free
• tasty (or so I’m told): descriptions of their flavor vary from nutty to citrusy to smoky and slightly crunchy.

In years when cicadas emerge, recipes for dishes containing cicadas emerge as well.

Then again, there are several good reasons to avoid making cicadas a part of your diet, including these:

• You just can’t get past the “ick” factor. Adventurous eaters may be willing to try or even embrace consuming cicadas, while others will be unable to view the idea as anything other than horrifying.
• You find the taste or consistency unappealing.
• You’re “cicada intolerant.” Some people get stomach upset, nausea, or diarrhea if they eat too many cicadas.
• You’re pregnant or breastfeeding, or are a young child. Concerns about even low levels of pesticides or other toxins in cicadas have led to recommendations that these groups not eat them. Doesn’t this suggest the rest of us should also steer clear? Well, thus far, at least, there’s no evidence that toxins in cicadas are causing health problems.

But there is one more very important entry on this list: people with a shellfish allergy should not eat cicadas. Odd, right?

The shellfish-cicada connection

Cicadas are biologically related to lobsters, shrimp, crabs, and other shellfish. So if you’re allergic to shellfish, you might also be allergic to cicadas. A particular protein called tropomyosin is responsible for the allergy. It’s found in shellfish as well as in many insects, including cicadas.

The allergic reaction occurs after eating the cicada. Just being around them or handling them won’t trigger a reaction.

Among people with a shellfish allergy, developing a reaction after eating cicadas could be a bigger problem than it seems: up to 10% of people have shellfish allergies and, as noted, insect consumption is common worldwide.

Is it okay for your dog or cat to eat cicadas?

Walking your dog after the emergence of cicadas can be a new and exciting experience for you and your pet! Dogs may chase after cicadas and eat them. Cats might, too, if given the chance. That can be a problem if your pet eats too many, as some will experience stomach upset or other digestive problems.

While the insects are considered harmless to dogs, the American Kennel Club says it’s best to steer them away from cicadas once they’ve eaten a few.

Which other insects trigger allergies?

While insect-related allergic reactions (think bee stings) and infections (like Lyme disease) are well known, the insect-food-allergy connection is a more recent discovery.

One recently recognized condition is the alpha-gal syndrome, in which a person bitten by certain ticks develops an allergy to meat. The name comes from a sugar called galactose-α-1,3-galactose (or alpha-gal) found in many types of meat including beef, lamb, pork, and rabbit. According to the CDC, up to 450,000 people in the US may have developed this condition since 2010.

There aren’t many rigorous studies of the overlap of insects and food allergies, so there are probably others awaiting discovery.

The bottom line

When it comes to eating cicadas, I’ll pass. It’s not because of the risks. I’ve never had a problem with shellfish, and for most people the health risks of eating cicadas seem quite small. It’s just unappealing to me, and I’m not a particularly adventurous eater.

But let’s go easy on those who do enjoy snacking on cicadas. Insects offer a good source of calories and protein. Just because eating them seems unusual in the US doesn’t make it wrong.

So, if you like to eat cicadas and have no shellfish allergy or other reason to avoid them, go for it! This may be a very good summer for you.

About the Author

Robert H. Shmerling, MD, Senior Faculty Editor, Harvard Health Publishing; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Robert H. Shmerling is the former clinical chief of the division of rheumatology at Beth Israel Deaconess Medical Center (BIDMC), and is a current member of the corresponding faculty in medicine at Harvard Medical School. … See Full Bio View all posts by Robert H. Shmerling, MD

Americans love their ultra-processed foods, whether they come as cereal (like Cap’n Crunch, a favorite of mine as a kid), snack foods (like Cheetos), entr’es (like hot dogs), or desserts (like Twinkies). Sure, loading your plate with vegetables, fruits, fish, healthful oils, and grains in a Mediterranean-style diet boosts heart and brain health. But if you also eat some ultra-processed foods, is that bad for your brain health?

What to know about this new study

A new study appears to deliver resounding yes: eating ultra-processed foods is linked to a greater risk of cognitive impairment and strokes.

This well-designed observational study examined data from the REGARDS (REasons for Geographic And Racial Differences in Stroke) project, a longitudinal study of non-Hispanic Black and white Americans ages 45 years and older. Study participants were initially enrolled between 2003 and 2007 and were given a number of questionnaires evaluating health, diet, exercise, body mass index, education, income, alcohol use, mood, and other factors. In addition, tests of memory and language were administered at regular intervals.

To examine the risk of stroke and cognitive impairment, data from 20,243 and 14,175 participants, respectively, were found usable based on the quality of the information from the questionnaires and tests. Approximately one-third of the sample identified as Black and the majority of the remaining two-thirds identified as white.

The results of the study

• According to the authors’ analysis, increasing the intake of ultra-processed foods by just 10% was associated with a significantly greater risk of cognitive impairment and stroke.
• Intake of unprocessed or minimally processed foods was associated with a lower risk of cognitive impairment.
• The effect of ultra-processed foods on stroke risk was greater for individuals who identified as Black compared to individuals who identified as white.

Study participants who reported following a healthy diet (like a Mediterranean, DASH, or MIND diet) and consumed minimal ultra-processed foods appeared to maintain better brain health compared to those who followed similar healthy diets but had more ultra-processed foods.

Why might ultra-processed foods be bad for your brain?

Here are some biologically plausible reasons:

• UPFs are generally composed of processed carbohydrates that are very quickly broken down into simple sugars, equivalent to eating lots of candy. These sugar loads cause spikes of insulin, which can alter normal brain cell function.
• Eating ultra-processed foods is associated with a higher risk of metabolic syndrome and obesity, well-established conditions linked to high blood pressure, abnormal blood lipid levels, and type 2 diabetes.
• There are unhealthy additives in ultra-processed foods to change the texture, color, sweetness, or flavor. These additives disrupt the microbiome in the gut and can lead to gut inflammation that can cause
  • the production of microbiome-produced metabolites that can affect brain function (such as short-chain fatty acids and lipopolysaccharides)
  • leaky gut, allowing toxins and inflammatory molecules to enter the bloodstream and go to the brain
  • altered neurotransmitter function (such as serotonin) that can impact mood and cognition directly
  • increased cortisol levels that mimic being under chronic stress, which can directly impact hippocampal and frontal lobe function, affecting memory and executive function performance, respectively
  • an increased risk for Alzheimer’s, Parkinson’s, and other neurodegenerative diseases due to inflammatory molecules traveling from the gut to the brain.
• Because ultra-processed foods have poor nutritional value, people will often be hungry shortly after eating them, leading to overeating and its consequences.

The take-home message

Avoid processed foods, which can include chips and other snack foods, industrial breads and pastries, packaged sweets and candy, sugar-sweetened and diet sodas, instant noodles and soups, ready-to-eat meals and frozen dinners, and processed meats such as hot dogs and bologna. Eat unprocessed or minimally processed foods, which — when combined with a healthy Mediterranean menu of foods — include fish, olive oil, avocados, whole fruits and vegetables, nuts and beans, and whole grains.

About the Author

Andrew E. Budson, MD, Contributor; Editorial Advisory Board Member, Harvard Health Publishing

Dr. Andrew E. Budson is chief of cognitive & behavioral neurology at the Veterans Affairs Boston Healthcare System, lecturer in neurology at Harvard Medical School, and chair of the Science of Learning Innovation Group at the … See Full Bio View all posts by Andrew E. Budson, MD