Is it possible to draw conclusions about an adult's physical condition on the basis of their age? The answer is: "It depends." On the one hand, it is well known that the body's ability to function decreases with age, while the risk for age-related illnesses increases over time. However, two people with the same age can also differ considerably in their physical aging and health. A person's chronological age and their biological age are only connected to a certain extent. This is because biological age reflects a person's actual physical aging process and depends on different factors such as their lifestyle, genetics and environment.