Biological aging represents the actual aging process or set of processes that cause the viability of organs to deteriorate over time. Chronological aging refers to the passage of time or simply reflects your date of birth and calendar year associated with aging.

Biological age (BA), often used to measure the progress of biological aging, can indicate an aging individual’s life expectancy (longevity), health-span and health status. Chronological age (CA) counts individuals’ years lived, not their functional level, life experience, or vulnerability to aging-related diseases and disabilities.

Consequently, people with the same CA might age differently, more likely due to variations in their fundamental biological aging mechanisms. BA is affected by various factors such as heredity, physical fitness, and external environmental stressors. If you are especially healthy and fit for your age, your biological age may well be lower than or same as your chronological age. But if you are sedentary, chronically ill, or in poor physical condition, your biological age may be higher.