Men have more heart attacks than women primarily because they lack the cardiovascular protection that estrogen provides, carry fat in more dangerous locations, and face higher rates of key risk factors like high blood pressure and heavy alcohol use. Before age 65, the gap is stark. After that, as women lose estrogen’s protective effects during menopause, the difference narrows considerably.
The reasons span biology, hormones, genetics, body composition, and behavior. No single factor explains the disparity on its own, but together they create a consistent pattern across populations worldwide.
Estrogen Protects Arteries in Multiple Ways
The biggest biological advantage women have before menopause is estrogen. This hormone keeps blood vessels flexible by triggering the production of nitric oxide, a molecule that relaxes artery walls and improves blood flow. Estrogen binds to receptors on heart and blood vessel cells, switching on genes involved in nitric oxide production, fat metabolism, and cell survival. It also lowers levels of an enzyme that causes blood vessels to constrict, keeping arteries more open and relaxed.
These aren’t subtle effects. In animal studies, removing estrogen’s influence leads to measurably worse heart function after a heart attack, while restoring it activates a network of protective genes involved in reducing inflammation and preventing cell death. Men produce small amounts of estrogen, and some of the same protective pathways can be activated in male blood vessel cells, but the overall exposure is far lower throughout life.
Testosterone’s Role Is More Complicated
Testosterone gets blamed for men’s higher heart attack rates, but the relationship isn’t straightforward. At normal levels, testosterone appears to have some anti-inflammatory effects by suppressing a key signaling pathway involved in plaque buildup inside arteries. Studies of men with low testosterone receiving replacement therapy generally show reductions in total cholesterol and LDL (the harmful type), with HDL (the protective type) staying stable or rising slightly.
The problems emerge at the extremes. Excessive testosterone, whether from natural overproduction or supplementation, can push red blood cell counts too high. This thickens the blood and increases the risk of clots, which is exactly how most heart attacks happen. Injectable testosterone in particular can temporarily spike red blood cell production and raise clotting risk. So while normal testosterone isn’t the villain it’s sometimes made out to be, it doesn’t offer the kind of active vascular protection that estrogen does.
Where You Store Fat Matters
Men and women tend to store fat differently, and this has real consequences for heart health. Men are more likely to accumulate visceral fat, the type that surrounds internal organs deep in the abdomen. Women typically store more subcutaneous fat, the kind that sits just beneath the skin around the hips and thighs.
These two types of fat behave very differently. Visceral fat is metabolically active, releasing inflammatory compounds and disrupting how the body processes sugar and cholesterol. It’s strongly linked to heart disease, stroke, and diabetes. Subcutaneous fat is comparatively benign. One study found that the ratio of subcutaneous to visceral fat could predict metabolic risk factors in men with otherwise normal waist measurements, but the same ratio wasn’t a significant predictor in women. In other words, even men who don’t look overweight can carry hidden visceral fat that quietly raises their cardiovascular risk.
Men’s Blood Vessels React More to Stress
When men and women experience the same psychological stress, their cardiovascular systems respond differently. In controlled studies, men showed a 27% increase in cardiac workload (measured by the combined rise in heart rate and blood pressure) compared to a 19% increase in women. Men’s blood pressure jumped higher too: an average increase of 11.4 mmHg versus about 8 mmHg in women.
Men’s blood vessels also constricted more during stress, meaning the heart had to pump harder against greater resistance. Interestingly, after the stress ended, men’s blood vessel function actually improved temporarily, while women’s showed a slight decline. But the acute spike in pressure and cardiac demand during stress is what matters for heart attack risk, especially in someone whose arteries are already narrowed by plaque. Repeated episodes of intense cardiovascular stress response, day after day, year after year, contribute to arterial damage over time.
The Y Chromosome Carries Its Own Risk
Beyond hormones, the Y chromosome itself appears to contribute to heart disease risk. Research published in The Lancet identified a specific lineage of the Y chromosome, called haplogroup I, that is associated with higher rates of coronary artery disease in men. Men carrying this variant showed changes in 19 molecular pathways related to inflammation and immunity in their immune cells, many of which are directly relevant to the buildup of arterial plaque.
The implication is that some men carry a genetic predisposition, encoded on the chromosome that makes them male, toward chronic low-grade inflammation in the cardiovascular system. This isn’t something that affects all men equally, but it adds another layer to the biological explanation for why heart attacks skew male.
Higher Rates of Key Risk Factors
Biology aside, men also face more exposure to the lifestyle factors that cause heart attacks. Hypertension is more common in men than women through most of adulthood: about 15.5% of men versus 11.2% of women in large cross-sectional studies. This pattern holds across ethnicities and countries of origin, though it reverses after age 70, when women’s rates overtake men’s.
Alcohol consumption is the single largest contributor to the gender gap in hypertension, accounting for roughly 35% of the difference between men and women in decomposition analyses. Men also historically smoke at higher rates, though this gap has narrowed in many countries. Both habits directly damage arteries, raise blood pressure, and accelerate plaque formation. The combination of biological vulnerability and greater risk factor exposure creates a compounding effect.
Menopause Closes the Gap
The clearest evidence that hormones drive the gender difference comes from what happens after menopause. As estrogen levels drop, women’s cardiovascular risk climbs steadily. The gap in hypertension between men and women reaches its smallest point between ages 55 and 64, according to data from the National Health and Nutrition Examination Survey. After 65, a higher percentage of women have hypertension than men.
Heart attack rates follow a similar trajectory. Women don’t catch up completely, likely because decades of estrogen exposure provide some lasting structural benefit to arteries, but the protective advantage shrinks dramatically. This transition period is now recognized as a critical window for cardiovascular prevention in women.
Women’s Heart Attacks Are Also Underdiagnosed
Part of the statistical gap between men and women may reflect differences in how heart attacks are recognized. Women are significantly more likely to present with what doctors call “atypical” symptoms: dizziness, sweating, shortness of breath, nausea, back pain, and fatigue rather than the classic crushing chest pain. In one hospital study, 85% of women with confirmed heart attacks had these atypical presentations, compared to 70% of men.
These differences lead to delays. Women are more likely to attribute their symptoms to something else, more likely to try over-the-counter remedies before seeking help, and more likely to face delayed diagnosis once they reach a hospital. This doesn’t mean women are having heart attacks at the same rate as men (they aren’t, especially before menopause), but it does mean that some of the apparent gap reflects missed or delayed diagnoses rather than a true absence of disease. Recognizing that heart attacks can look different in women is important for both patients and the people around them.