Globally, people are living longer but are also spending more years coping with ill health, a trend most pronounced in the United States. This phenomenon, known as the "morbidity gap," is the difference between a person's total life expectancy and their healthy life expectancy.
Researchers analyzing data from 204 countries and territories between 1990 and 2023 found that the morbidity gap has widened across most of the world. Globally, an average of 14.5% of life was spent in poor health in 2023, an increase from 13.6% in 1990. During the same period, global life expectancy at birth rose from 64.6 years to 73.8 years, while healthy life expectancy increased from 55.9 years to 63.1 years.
In the United States, the morbidity gap is approximately 14 years, representing about 17.8% of the expected lifespan. This widening gap is particularly evident in wealthier nations with greater access to life-extending resources. The study also noted that while women live longer than men, they also tend to spend more years in poor health.
Dr. Antony Chu, clinical assistant professor at Brown University’s Warren Alpert School of Medicine, observed that while modern medicine has made significant strides in reducing mortality from various diseases, these advancements have not always kept pace with the decline in functional health. "Many of those additional years are now lived with chronic pain, disability, sensory loss, depression or reduced independence," Chu stated.
The primary contributors to years lived in poor health worldwide are musculoskeletal disorders, mental health conditions such as depression and anxiety, hearing loss, and falls. Other significant factors include high fasting plasma glucose, obesity, and aging populations. These largely non-fatal conditions account for a substantial portion of the increased time spent in ill health.
Experts suggest that future improvements in population health will require not only extending lifespan but also enhancing healthspan—the number of years individuals live in good health. This involves greater investment in disease prevention, long-term disease management, and chronic care.
Dr. Christopher Murray, director of the Institute for Health Metrics and Evaluation (IHME) at the University of Washington School of Medicine and a senior author of the study, emphasized the need to measure progress in healthy aging by healthspan, not just lifespan. "Progress in healthy aging should be measured not only by lifespan, but by healthspan," Murray said. "This requires greater investment in prevention, long-term disease management and chronic care to reduce years lived in poor health."
To effectively address the declining healthspan, a shift in focus is recommended from merely reacting to disease to preserving function. This approach includes regular assessments of mobility, muscle strength, balance, hearing, and cognition, as well as early intervention strategies. Musculoskeletal health, in particular, is highlighted as an area needing greater emphasis, with progressive resistance training, fall prevention, and early treatment of chronic back pain suggested as key components of preventive medicine.
Mental health and social connection are also identified as critical factors for healthspan. Chu noted that hearing loss, depression, anxiety, and loneliness can exacerbate physical decline and diminish quality of life. Addressing these conditions early could improve both longevity and independence. He also pointed to the cultural dimension of healthy aging, where in many societies, older adults maintain active and respected roles within families, contributing to a sense of purpose and belonging. In contrast, many older Americans experience social isolation, which can negatively impact their health and well-being. The research suggests that healthy aging is shaped not only by biology but also by community, purpose, and human connection.