At the turn of the 20th century, women had a life expectancy just two years higher than men, Dr. Yan said. But over the next 75 years, that gap began to widen, largely because more men smoked and developed cardiovascular disease or lung cancer.

As smoking rates declined, excess deaths reduced among men, in particular.

But in 2010, that gender gap began to widen yet again, this time driven by opioid overdose death rates, which are more than twice as high for men. That year, the life expectancy for men was 76.3 years, while for women it was 78.1.

Men had a greater risk of developing diabetes and heart disease, and also faced higher rates of homicide and suicide.

More than 1.1 million people in the United States have died of Covid, a staggering death toll that has caused precipitous declines in life expectancy. Between 2019 and 2021, the life expectancy in the United States dropped from around 79 to 76 years.

But men have died of Covid at a higher rate than women. The reasons for this are complicated. Biological factors, like differences in inflammation and immune responses, likely played a significant role.

But social and behavioral differences mattered, too. Men are more likely to work in industries with higher rates of Covid exposure and fatalities, including transportation, agriculture and construction, or to experience incarceration or homelessness. Women are also more likely to be vaccinated.

From 2019 to 2021, Covid was the leading contributor to the widening gap in life expectancy between men and women, contributing nearly 40 percent of the difference in years lost.

Unintentional injuries — mostly drug overdoses — contributed to more than 30 percent of the life expectancy gap between men and women. But more men also died by homicide or suicide between 2019 and 2021.

“All of these point to a picture of worsening mental health across the board, but particularly among men,” Dr. Yan said.

Dr. Yan noted that his analysis did not include transgender or other gender identities, because death certificates do not record that information.