Adults under 65 who live alone had a 22% higher risk of death than those who live with others, compared with 6% for older adults

More Americans live alone than ever before, and most of the worry about it has focused on older people. Researchers at the American Cancer Society looked at the whole adult population instead. They linked national health survey answers from 598,023 US adults, collected between 1998 and 2018, to death records, comparing people who lived alone with people who lived with others. They looked at deaths from all causes and from 15 specific causes, separately for adults under and over 65.

The surprise was in the younger group. Adults aged 18 to 64 who lived alone had a 22% higher risk of dying from any cause than those who lived with others. For adults 65 and older, the difference was just 6%.

Among the younger group, living alone was linked to a 58% higher risk of death by suicide, 41% higher from heart disease, 34% higher from diabetes, 27% higher from colorectal cancer and from injuries, 23% higher from stroke, and 17% higher from accidents. Older adults living alone had higher risks of death from suicide, high blood pressure, injuries and heart disease.

“Living alone is not necessarily harmful or a suboptimal living arrangement,” said lead author Hyunjung Lee, principal scientist of cancer disparity research at the American Cancer Society. “However, our findings indicate that excess deaths among adults living alone compared to living with others are largely concentrated among individuals with existing health conditions and high-risk health exposures.”

Much of the gap could be explained. Differences in income, education, existing illness, smoking, heavy drinking and access to care accounted for about 57% of the extra deaths among younger adults living alone, and about 85% among older adults. The researchers note that people living alone, particularly men, middle-aged adults and non-Hispanic white adults, were more likely to smoke and drink heavily.

The findings fit a large body of research on social connection. A 2015 meta-analysis in Perspectives on Psychological Science led by Julianne Holt-Lunstad found that living alone, social isolation and loneliness were each linked to roughly a 26% to 32% higher risk of early death. But living alone is not the same as being lonely. Some research suggests the risk is concentrated among people who live alone and are also socially isolated.

The second finding is why age may matter. Older adults living alone are already the focus of many check-in programs and health services. Younger adults living alone may fall through the cracks, the researchers suggest, with no one noticing a missed medication, a worsening mood or an injury.

“Policy and clinical practice efforts are needed to identify modifiable risk factors that contribute to this higher risk of death among those living alone, including chronic disease management, injury prevention, improved access to preventive care and early detection, and screening for mental health conditions,” Lee said. Who we live with shapes health in other ways too, from marriage and biological aging to how one partner’s sleep affects the other’s diet.

For people who live alone, the practical points are simple ones: keep up with checkups, have someone who checks in regularly, and take mood changes seriously. If you are struggling, talking to someone you trust or a doctor is a good first step, and crisis lines are available in many countries.

There are limits to what this shows. The study is observational, living arrangements were recorded once, and the data cannot show whether living alone causes poorer health or whether people with health problems are more likely to live alone. Living alone does not measure loneliness or social contact directly.

Source

Lee H, Bispo J, Singh G, et al. “Living alone and risk of mortality from all-cause and 15 specific causes: a nationally representative cohort study of US adults.” International Journal of Epidemiology, 2026.
DOI: 10.1093/ije/dyag211

Also cited

Holt-Lunstad J, Smith TB, Baker M, Harris T, Stephenson D. “Loneliness and social isolation as risk factors for mortality: a meta-analytic review.” Perspectives on Psychological Science, 2015.
DOI: 10.1177/1745691614568352