People are living longer than ever before.
This is one of the greatest achievements of modern medicine. Better prevention, safer surgery and more effective treatments have helped millions of people survive conditions that once shortened life.
But living longer does not always mean living healthier.
A large international analysis of national health data from 183 World Health Organization (WHO) member states, representing populations across every continent over a period of almost 20 years, found that life expectancy is increasing faster than the number of years people live in good health.
The difference between these two periods is called the healthspan-lifespan gap.
Lifespan describes how long we live.
Healthspan describes how long we remain healthy, active and independent, without disease or disability significantly limiting everyday life.
The gap between them represents the years spent living with reduced health.
Worldwide, this gap now approaches ten years.
This does not mean that every person will spend exactly ten years in poor health. It is a population measure, not an individual prediction. However, it reveals an important global pattern: many of the additional years gained through modern medicine are lived with chronic disease, disability or reduced independence.
A person may live longer after developing cardiovascular disease, diabetes, cancer or a neurological condition because treatment has become more effective. This is an important medical success.
But treatment does not always restore full health.
A person may still need several medications, experience reduced mobility or depend on regular medical care. Life has been extended, but health has not necessarily been preserved to the same extent.
This changes how we should think about longevity.
The goal should not be only to help people reach an older age. It should also be to delay the moment when chronic disease begins to affect their energy, mobility, cognitive health and independence.
This is why longevity medicine places so much importance on early prevention.
Cardiovascular risk, abnormal glucose regulation, loss of muscle mass, poor sleep and declining physical capacity often develop gradually. They may be present long before a person receives a major diagnosis.
Recognising these changes early creates an opportunity to intervene while health can still be protected.
Preventing disease is more valuable than simply treating it later.
This does not mean that every disease can be avoided. It means identifying individual risks early enough to delay disease, reduce its consequences and preserve health for longer.
The goal is not to stop aging. Aging is a natural biological process.
The goal is to improve the way we age so that more years are lived with physical strength, cognitive health, resilience and independence.
For many years, the success of medicine was measured primarily by life expectancy.
Today, another question is becoming equally important:
How many of those additional years are lived in good health?
