Can healthy aging be measured with a single number?
Not really.
Healthy aging reflects many different aspects of our health and function. No single blood test, scan or health measurement can capture the complete picture.
The World Health Organization approaches healthy aging as a multidimensional concept, involving physical and mental capacity, functional ability, well-being and the environment in which we live.
Why is healthy aging difficult to measure?
Aging does not affect every part of health in the same way or at the same pace.
Someone may have excellent cardiovascular and metabolic health but reduced mobility. Another person may remain physically strong while experiencing changes in cognition, vision or hearing.
Two people of the same chronological age can therefore have very different health profiles.
This is why healthy aging is better understood by looking at several dimensions together rather than relying on one measurement alone.
What should we look at?
A broader assessment of healthy aging may consider areas such as:
cardiovascular and metabolic health;
physical capacity and mobility;
cognitive and psychological capacity;
sensory capacity, including vision and hearing;
functional ability in everyday life;
overall well-being.
These areas can change differently over time and together provide a more complete picture of how health and function are being maintained as we age.
Why are multiple measurements useful?
Individual health measurements remain important.
Blood tests, imaging, physical performance, body composition and other clinical assessments can each provide valuable information about specific aspects of health.
But each represents only one part of a much broader picture.
A more complete assessment therefore brings information from multiple areas together. Looking across different dimensions of health can help identify where health and function are being maintained and where opportunities for prevention or improvement may exist.
Why does this matter for longevity?
If the goal of longevity medicine is not simply to live longer but to remain healthier for longer, assessment also needs to look beyond lifespan or any single health marker.
Bringing together multiple dimensions — including cardiovascular and metabolic health, physical and mental capacity, functional ability and well-being — can provide a more comprehensive picture of healthy aging and how it changes over time.
This broader perspective can also help shift the focus from a single result toward what matters most: preserving health and function across the years ahead.
