You get home, flip on the light in an empty apartment, and the first thing you do is grab your phone, not because anything important is waiting there, just to hear some kind of voice. Sound familiar? You are not alone in that feeling, and this is not an exaggeration: in 2025, the World Health Organization named loneliness a cause of 871,000 deaths a year worldwide for the first time in its history. That is roughly 100 deaths every hour. There is a less obvious side to that number, more surprising than the statistic itself, and we will circle back to it at the end.
How many people actually live alone, across countries
A similar rise in single-person households shows up across developed countries, and not only there. In Russia, the 2021 national census found that almost 42% of households are a single person, 27.6 million people in total, up from around 22% in 2002, nearly doubling in twenty years. In the United States, Pew Research Center found in January 2025 that nearly one in four (24%) Americans aged 18-29 feel lonely or isolated most or all of the time.
Here is the twist, though. If you assume this only happens in wealthy developed countries, a large study in the Journal of Adolescent Health (2023) breaks that assumption. Researchers covered 70 countries across Africa, Asia and the Americas at once, surveying 248,017 teenagers aged 13-17 across all five WHO regions. Average loneliness prevalence among them was 11.7%, with an enormous spread by country, from 2.2% in Laos to 25.9% in Afghanistan. Adolescent loneliness runs highest in Africa and the Eastern Mediterranean.
Why loneliness is more dangerous than it sounds
For a long time, loneliness got treated as an unpleasant feeling you simply push through, like a bad mood after a hard day that fades in a couple of evenings. Turns out it runs deeper than that.
In May 2023, the US Surgeon General, the country's top public health official, released a report titled "Our Epidemic of Loneliness and Isolation." Even before the COVID-19 pandemic, about half of American adults reported measurable loneliness. The report draws on a 2010 meta-analysis of 148 studies (a meta-analysis pools the results of many separate studies into one combined, more reliable estimate), and its conclusion lands hard: the mortality risk from social disconnection is comparable to smoking up to 15 cigarettes a day, and higher than the risk from obesity or physical inactivity.
Here is what that looks like in disease-specific numbers. Weak social ties raise the risk of cardiovascular disease by 29%, stroke by 32%, and, in older adults, dementia by 50%.
People aged 15-24 were hit hardest: their in-person social interaction time dropped 70% in 2020 compared to the prior two decades, and it never fully bounced back.
The WHO called loneliness a global health issue for the first time
On June 30, 2025, the WHO Commission on Social Connection published the organization's first-ever report on the topic. The headline finding: one in six people worldwide struggles with loneliness, and social isolation is linked to roughly 871,000 deaths a year, more than some major infectious diseases claim over the same period.
Two groups get hit hardest: adolescents and young adults (about one in five) and people in lower-income countries (nearly one in four). The WHO now explicitly calls social connection a "third pillar" of health, standing alongside the physical and the mental, not a secondary factor.
What is actually driving the numbers
Several forces are pushing loneliness up at once, not one single villain. Here are the main ones:
- Demographics. People live longer and families have shrunk, so older adults are more likely to end up alone once grown children move out and a spouse dies or a relationship ends.
- Housing economics. A studio apartment became physically more accessible (fewer rooms, lower price), so living solo got logistically easier over the last 30 years, even when it is emotionally harder.
- Work and relocation. Young people change cities for career reasons more often, losing an established circle of friends before building a new one.
- Digital contact instead of in-person contact. A messaging thread creates the illusion of connection, but it does not produce the same physiological effect as a face-to-face meeting.
What actually helps
Now for that less obvious side of 871,000. The relationship between loneliness and health runs both directions: rebuilding contact lowers the same risks that isolation raises. This is not just comfort talk, it is a measurable, reversible process.
- Count not the number of friends on social media, but the number of people you could call at three in the morning. That is a more honest measure of your social support.
- Schedule in-person time the way you would schedule a work meeting. "We should hang out sometime" almost never turns into an actual meetup.
- If you are an older adult, or care for one, treat social contact as part of medical care, not a nice-to-have. The dementia and stroke risk reductions track directly with more in-person connection.
- Start small: one recurring ritual (a weekly lunch with a coworker, a Sunday call to your parents) works better than one big attempt to suddenly "become social."
Back to that empty apartment and the phone in your hand. 871,000 deaths a year is not an abstract statistic happening somewhere far away, it is the sum of evenings just like that one, multiplied across years. Tending to your relationships is as much a part of health as sleep, food, and movement. Next time your hand reaches for the phone in an empty apartment, call an actual person instead of opening the feed.
Sources
