Why Do Women Live Longer Than Men?

Women outlive men almost everywhere in the world. The gap is one of the most consistent patterns in the study of death. But what causes it? The answer, researchers say, is not just one thing. This article explains what the data show and what the main explanations are.

How big is the gap?

In the United States, nearly five years. The CDC reports that life expectancy at birth in 2024 was 81.4 years for females and 76.5 years for males, which is 4.9 years of difference. The gap has narrowed from about 5.3 years in 2023, when the figures were 81.1 and 75.8, because male life expectancy rose more. The gap also persists later in life: at age 65, women could expect 20.8 more years and men 18.4 more years, a difference of 2.4 years.

Is it true everywhere?

Almost. A review in PubMed Central states that males live shorter lives than women in all countries. But the size of the gap is not constant. It notes that a few countries had longer male life expectancy before 2006, and that in 2005 there were still four countries where women lived shorter lives than men. That the gap varies so much suggests it is not driven only by biology.

What does biology explain?

Part of it. ScienceInsights says estrogen appears to give some protection against cardiovascular disease and overall death during a woman’s reproductive years. After menopause, when estrogen falls, women’s heart disease rates begin to catch up with men’s. The PubMed Central review adds that basic cell-level measures suggest men age faster than women, but even these results come from a combination of biology, behavior, and social factors.

What does behavior explain?

A lot, especially smoking. ScienceInsights says cigarette smoking has historically been the single largest behavioral contributor to the difference in death rates between the sexes. A public health school at Kent State explains that the gap widened in the middle of the 20th century because of the early, widespread adoption of cigarette smoking among men. ScienceInsights also reports that men have been quitting smoking in larger numbers and earlier. Male heart disease death rates have fallen faster than female rates. This helps explain why the gap is narrowing.

What about marriage and other social factors?

They matter too. ScienceInsights reports that marriage has a notable protective effect on health and that it benefits men more than women. The PubMed Central review treats differences in the medical, social, and epidemiological conditions in which men and women live as one of three main explanations, along with biology and behavior.

Why is the gap changing?

Because risks change. The CDC says life expectancy overall rose to a record 79.0 years in 2024, largely because deaths from unintentional injuries, COVID-19, heart disease, cancer, and homicide decreased. As the leading causes shift, so does the gap. For the bigger picture, see How the Life Expectancy of Americans Changed Over the Last Century and What Are the Leading Causes of Death in the United States?.

Does this mean every woman will outlive every man?

No. These are averages across millions of people. Individual lives depend on health, genes, habits, and luck. For the biology of aging, see Why Do We Age and Die?.