Social isolation: what is it and why is it important to your health?

The Bottom Line

Social isolation should be considered a health risk. We need more scientific evidence about how to deal with social isolation.

Why is social isolation a health problem?

Human beings are social animals. We live with others, and we support each other; that’s what has given us an evolutionary advantage. So what happens when a person doesn’t have others to be with – when they are socially isolated? Older people are especially at risk of being socially isolated. By the time people reach their eighties, the majority live on their own, mostly because of widowhood. This is particularly the case for older women who are more likely to be widowed than older men. Older people’s social networks often get smaller for other reasons as well – children may have moved away, along with grandchildren, and aging siblings and friends may have died.

What does the research (scientific evidence) show us about those who are socially isolated?

For many decades, researchers have been interested in social isolation and what impacts it has on people’s health. One question that has been looked at is whether people who have more social relationships or more supportive relationships live longer than those with fewer or less supportive ones. In these studies, people are asked about their social relationships at one point in time; some years later, researchers follow up and determine who is still alive and who has died in the meantime. In one study (1) researchers reviewed 148 studies that had previously looked at social relationships and mortality. Across the 148 studies, people with more or better social relationships lived longer.

Other research has looked at what kinds of social activities people participate in and what health effects they have on them. For example, in a large and well conducted study (2), people were asked about social activities they engaged in, like visiting relatives or friends or participating in groups such as senior centres. They were also asked whether they had any disabilities. About 5 years later, people were interviewed again and asked again about their disabilities. From this, researchers were able to determine who had become disabled since the first interview. The researchers found that more socially engaged people were less likely to have become disabled (43% less likely), and this even after taking other important factors into account, such as physical activity.

We need to be somewhat careful in interpreting these findings, though, because it is possible that other factors are at play. People who are socially isolated may be different from those who are not in many other ways besides social isolation; for example, genetically, in their behavior, or in some other way. Researchers try to take many of these other possible factors into account in their studies, but they can’t take all factors into account. This means that we can’t say social isolation is a cause of health problems; all we can say is that it’s a risk factor that increases the likelihood of experiencing health problems.

The research evidence is less clear about what we can do to reduce social isolation. The obvious answer would seem to be to get people connected to each other and many programs are available that try to do just that. For example, there are many clubs or senior centres that allow people to get together. We lack good evidence, though, that shows that such programs in fact reduce social isolation and, ultimately, produce health benefits. We also don’t know whether they reach those most at risk of being socially isolated. If people don’t come forward on their own it can be a challenge to identify those who are socially isolated and help them to become more socially engaged.

What can you do to help those who are socially isolated?

Many older adults are socially isolated. This should be of concern to all of us, as family members, caregivers, service providers, or neighbours. We need to watch out for older people who live alone, who hardly ever go out of the house, who hardly ever get visitors. Making a phone call to or visiting a family member or checking on a neighbour doesn’t take much time, but could make a big difference in somebody’s life. Communication via the internet also makes it increasingly easy to stay in touch across geographic distances. And there are many organizations that provide opportunities for social engagement, such as senior centres. Service providers should be aware of these opportunities and refer their clients that may be socially isolated to them.

Get the latest content first. Sign up for free weekly email alerts.
Author Details


  1. Holt-Lunstad J, Smith TB, Layton JB. Social relationships and mortality risk: a meta-analytic review. PLoS Med 2010 Jul;7(7):e1000316.
  2. James BD, Boyle PA, Buchman AS, Bennett DA. Relation of late-life social activity with incident disability among community-dwelling older adults. J Gerontol A Biol Sci Med Sci 2011 Apr;66(4):467-73.

DISCLAIMER: These summaries are provided for informational purposes only. They are not a substitute for advice from your own health care professional. The summaries may be reproduced for not-for-profit educational purposes only. Any other uses must be approved by the McMaster Optimal Aging Portal (

Many of our Blog Posts were written before the COVID-19 pandemic and thus do not necessarily reflect the latest public health recommendations. While the content of new and old blogs identify activities that support optimal aging, it is important to defer to the most current public health recommendations. Some of the activities suggested within these blogs may need to be modified or avoided altogether to comply with changing public health recommendations. To view the latest updates from the Public Health Agency of Canada, please visit their website.