New research suggests that the first step to preventing and treating illness is asking a simple question: What’s your sex? Here’s why—and what it means for you.

By Laura Schocker
Updated February 04, 2015
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Illustration: scientists projecting images of man and woman
Credit: Jeannie Phan

Everyone knows what a heart attack looks like: You clutch your chest, grab your left arm, then fall to the ground. That is, if you’re a man. But for a woman, most of us know the symptoms can be strikingly different: In fact, half of women report experiencing no chest pain at all. Instead they may feel pain in their backs, necks, jaws, or stomachs, or become nauseated, fatigued, or light-headed.

This difference wasn’t fully documented or publicized until 1990, when the book The Female Heart: The Truth About Women & Coronary Artery Disease helped spark a new wave of thinking about not only heart disease but also medicine and the human body. “We [once] assumed all humans were pretty much the same, except for what I call the bikini view of women—their breasts and their pelvises,” says Marianne Legato, M.D., the director of the Foundation for Gender-Specific Medicine and the first author of The Female Heart. Today the thinking has changed. “Every tissue of the body is literally different in men and women,” says Legato. And heart disease, scientists have discovered, is just one of many conditions with a strong male-female divide. Here are six others that affect the sexes in distinctive ways.

Alzheimer’s Disease

The stats: An estimated 5 million people in the United States ages 65 and older have Alzheimer’s disease, an aggressive, premature deterioration of the brain that results in dementia. Women make up 64 percent of this population. The disease often progresses more quickly in women—particularly when it comes to memory loss—than in men, says Reisa Sperling, M.D., director of the Center for Alzheimer’s Research and Treatment at Brigham and Women’s Hospital, in Boston.

The gender gap: The high female prevalence of this illness can partially be attributed to the fact that women live longer than men, and that the disease typically afflicts the elderly. But there’s more to the disparity than life span: A 2014 Annals of Neurology study showed that healthy women who carry the gene variant ApoE4 have an 80 percent chance of developing cognitive decline or Alzheimer’s disease; men with the same gene only have a 27 percent risk.

Good to know: Can’t remember where you left your keys or the name of the actor in the movie you saw last night? Relax: These are common signs of perimenopause (which usually occurs between ages 45 and 55). Memory loss in Alzheimer’s is more dramatic: You might repeat a conversation twice in an hour or get lost in your own neighborhood. But you should see your doctor if you’re concerned, especially if you have a family history of the disease.

Colorectal Cancer

The stats: The overall risk of colo­rectal cancer is about 5 percent for both men and women, but mortality is lower in women.

The gender gap: A 2013 review in Clinical Chemistry and Laboratory Medicine showed that women tend to develop colorectal cancer five years later than men, and that their tumors are typically located in the right side of the colon, whereas men’s are in the left. The location has serious implications, says Gina Sam, M.D., M.P.H., the director of the Mount Sinai Gastrointestinal Motility Center at the Mount Sinai Hospital, in New York City. Because the right section of the colon (or the proximal colon) is bigger than the left section, it takes longer for tumors that grow there to become large enough to present visible bleeding. That’s probably why women receive colorectal cancer diagnoses at more advanced stages than men do. So why do more women than men survive? Research suggests that it may be because women respond better to some chemical treatments.

Good to know: It’s not easy to detect early-stage cancer in the right colon, but it is possible. Bloating and severe constipation are two major symptoms. Preventive screening—starting at age 50 for most people, sooner for those with a family history of the disease—also saves lives.


The stats: At some point in their lifetime, roughly 20 percent of women and 10 percent of men experience depression, a syndrome characterized by persistent feelings of sadness or loss of interest, plus sometimes feelings of guilt, worthlessness, or hopelessness. Women are more likely than men to attempt suicide, but men more often die from the attempt.

The gender gap: Differences in men’s and women’s brain structures and hormones may explain the split in prevalence. It could also stem from the disparate upbringings of boys and girls, as well as “rates of abuse, women’s tendency to use internalizing coping styles, and their disadvantaged social status,” says Susan Kornstein, M.D., the executive director of the Institute for Women’s Health at Virginia Commonwealth University, in Richmond. As for symptoms, women usually suffer from increased appetite, weight gain, hypersomnia (sleeping too much), anxiety, and physical pain. Men tend to exhibit insomnia, weight loss, and irritability.

Good to know: Research suggests that women respond better to selective serotonin reuptake inhibitors (such as Prozac) and monoamine oxidase inhibitors (like Nardil) than tricyclic antide­pres­sants (such as Sinequan). Women should also be aware that doctors can mistake depression for premenstrual dysphoric disorder (PMDD) and vice versa. PMDD usually presents as severe irritability that strikes just before your period, then subsides a few days later. To distinguish between the diseases, track how you feel the week after your period. If you have PMDD, you should be symptom-free.

Migraine Headaches

The stats: Women outnumber men three to one when it comes to migraine, a severe, pounding head pain often accompanied by sensitivity to light, sound, and smells; nausea; and blurred vision.

The gender gap: According to Andrew Charles, M.D., the director of the Headache Research and Treatment Program at the David Geffen School of Medicine at UCLA, female hormones play a big role in migraine headaches, which may be why attacks often worsen around your period and improve after menopause and during pregnancy. Male and female contrasting brain structures could also play a part. Charles’s experiments on mice showed that female brains expe­rience more activity and excitability than male brains do—and as a result may be more easily triggered to launch a migraine.

Good to know: There’s some evidence that migraine associated with menstruation is more difficult to treat. If your headaches coincide with your period, see a specialist.

Sleep Apnea

The stats: About 25 percent of men and nearly 10 percent of women suffer from this disorder, in which breathing stops for short periods during sleep.

The gender gap: Female sex hormones seem to protect against apnea, which partially explains why a woman’s risk increases after menopause, when hormones dip, says Grace Pien, M.D., an assistant professor of medicine at the Johns Hopkins University School of Medicine, in Baltimore. Another factor: Men’s airways are longer and thus more prone to collapse.

Good to know: When men have apnea, they snore loudly and get sleepy during the day. Female symptoms may be subtler: They may not snore at all. Instead, women usually complain of fatigue, mood changes, or the inability to be efficient. As a result, women—and their doctors—are less likely to suspect apnea as the cause of their symptoms. “Women are more likely to be evaluated for hypothyroidism or depression first,” says Pien.


The stats: Men have a higher risk of stroke (when blood stops flowing to the brain) until age 85. That’s when the risk for women skyrockets. “Stroke outcomes are also different in women and in men,” says Janine Austin Clayton, M.D., the associate director of research on women’s health at the National Institutes of Health. Women’s strokes more often are fatal or result in a poor quality of life.

The gender gap: In addition to the universal symptoms (numbness and weakness in the face, arms, or legs; confusion; difficulty speaking or walking), women also experience sudden hiccups; face, limb, or chest pain; nausea; and exhaustion.

Good to know: Taking a low-dose aspirin each day may help. The drug doesn’t reduce a woman’s risk of having a first heart attack (as it does for men), but research shows it may lessen a woman’s likelihood for some strokes. And consider dropping hormonal birth control: It can increase the risk of stroke in women over the age of 35 and those who smoke or have high blood pressure, diabetes, or high cholesterol.