We Live Longer — Yet Spend Many More Years in Illness

We have added years to life. But many of those years arrive with aches, confusion, and limits. How did longevity become a longer stretch of frailty for so many?

A major new analysis of data from 204 countries paints a clear, unsettling picture: global life expectancy has climbed to about 73.8 years, a triumph built on slashing infectious diseases, cutting maternal and child deaths, and better managing chronic illness. Success, yes. But success with a caveat. The extra years aren’t all healthy years.

In 2023, people worldwide spent on average 14.5% of their lives in poor health. The twist is that the healthiest-looking nations on paper—those with the highest life expectancy—also register larger shares of life lived with disability. Residents of the wealthiest countries spend roughly 15.7% of their lives in a state of disability. In some parts of Africa the share is lower. Why? Because living longer has often extended the period of age-related decline rather than postponing it.

What fills those troubled years? The study finds that nonfatal conditions carry the main burden. Musculoskeletal problems—low back pain among them—mental health disorders, sensory losses like age-related hearing impairment, and accidental injuries account for 57.4% of the gap between years lived and years lived in good health. On the risk side, high body-mass index, undernutrition, tobacco use, high blood sugar and air pollution stand out as major drivers.

Researchers argue that societies should aim for a longer healthy lifespan—not just a longer lifespan.

The implications reach beyond medicine. Economic models in the study suggest that investing in healthy aging and preventing disability delivers far greater payoff than strategies focused only on eradicating a single disease or simply pushing up average lifespan. In other words, a dollar spent to keep someone active, mobile and mentally sharp often returns more value to communities than a dollar spent only to extend life by a year.

The findings appear in The Lancet Public Health and carry a simple, stubborn challenge: if we've learned how to lengthen the calendar of life, can we now learn to fill those extra pages with quality rather than frailty? The question is no longer just how long we live, but how well we live those years.