November 2, 2026, 5:10 pm | Read time: 5 minutes
It is now known that social isolation can significantly impair quality of life and negatively affect health. In a large-scale study, researchers examined whether adults living alone die more frequently from certain diseases than those living with others, and what other factors might play a role. The analysis showed, among other things, an increased risk in the age group between 18 and 64 years.
How Exactly Does Living Alone Increase Mortality?
FITBOOK has already reported on various studies showing that loneliness can cost healthy years of life.1,2 It is believed that loneliness is often associated with psychological stress–such as anxiety and depression–and can also promote suicidal thoughts. Physical illnesses are also a threat. According to previous studies, cardiovascular diseases and type 2 diabetes appear to occur more frequently in lonely people.3
The present study took a different approach.4 The authors aimed to find out whether certain causes of death are indeed more common among people living alone than among those living with others. It is important to note: Living alone does not necessarily mean being lonely. Therefore, the researchers examined to what extent personal living conditions and health factors can explain the observed differences in mortality. Two age groups were compared: adults aged 18 to 64 and those aged 65 and older.
Study Details
The researchers used data from the National Health Interview Survey, which regularly surveyed U.S. adults on health topics between 1998 and 2018.5 A total of 598,023 adults were included.
The researchers linked the survey data with a U.S. registry, specifically with information on deaths contained therein. The follow-up continued until 2019, allowing the scientists to track how mortality developed among people with different living situations over time.
For statistical analysis, Cox proportional hazards models were used. These methods allow for comparing the mortality risk of different groups while considering the time until the respective event. The results are presented as hazard ratios (HR). A value of 1 means there is no difference between the compared groups, while values above 1 indicate a higher relative risk.
Additionally, the researchers used the Blinder-Oaxaca decomposition to estimate the extent to which observed characteristics can explain the differences between groups.
Results
The analysis found that adults living alone had a higher mortality risk for several causes of death compared to those living with others. The researchers noted significant differences between the two age groups.
Overall Mortality and Heart Diseases
For overall mortality, the relative risk for adults living alone aged 18 to 64 was 22 percent higher than for those living with others. Among those over 65, the difference was still 6 percent.
The results were even more pronounced for heart diseases. Here, the mortality risk was 41 percent higher in the younger age group and 11 percent higher in the older group.
Suicides and Injuries
Adults living alone aged 18 to 64 were 58 percent more susceptible to deaths by suicide. For those over 65, it was more than double (103 percent). Deaths from injuries were also more common among those living alone, with the risk being 27 percent higher for the younger group and 16 percent higher for the older group.
Other Causes of Death
Additionally, among those aged 18 to 64, there were increased mortality risks from strokes (23 percent), colon cancer (27 percent), diabetes (34 percent), and accidents (17 percent). For those over 65, there was a 28 percent increased mortality risk from hypertension.
An interesting finding of the study is that living situation alone does not seem to fully explain the differences in mortality. Personal living conditions and health status also appear to play a significant role. Such factors explained 57.1 percent of the difference for those aged 18 to 64 and even 85.4 percent for those over 65. However, the specific characteristics that were particularly significant are not clear from the study results–possible factors could include financial situation, lack of social contacts, and similar issues.
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Significance of the Results
The study highlights once again that living situation can be an important factor in assessing health risks. A particularly noteworthy finding is that the connections do not exclusively affect older people–in some cases, quite the opposite. The differences were even more pronounced for several causes of death among those living alone aged 18 to 64.
The study provides an important insight for health care: People living alone should not be automatically classified as at health risk. After all, the results show that other personal and health characteristics also significantly contribute to the differences in mortality. It is all the more important to consider possible risk factors individually–living situation alone should not be the sole measure.
The authors emphasize that the topic deserves more attention, especially among younger and middle-aged adults. For them, the differences in several causes of death were sometimes more pronounced than for older people.
Limitations
As an observational study, the research cannot prove a causal relationship. It remains unclear whether living alone itself contributes to increased mortality or whether the observed health risks are more due to other factors related to the respective living situation. It is also not clear which of the examined characteristics are actually decisive for the increased mortality risks.
Another limitation is that the study only included adults from the U.S. Since social structures, living conditions, and health systems vary from country to country, the results cannot be easily applied to other populations (such as in Germany).
Help with Suicidal Thoughts
If you have suicidal thoughts or know someone who is affected, you can contact the suicide prevention hotline. You can receive anonymous help around the clock at the toll-free numbers 0800 111 0 111 and 0800 111 0 222. More information is available at www.telefonseelsorge.de.