What type of aging refers specifically to changes that are directly due to aging itself?

Primary aging refers to the natural, universal changes that occur in the body as it ages, which are independent of external factors or illnesses. This type of aging encompasses the biological and physiological processes that happen over time, such as graying hair, decreased bone density, and changes in skin elasticity. These changes are largely predictable and are a fundamental part of the aging process that affects everyone, regardless of lifestyle or environmental factors.

Unlike secondary aging, which refers to age-related changes due to lifestyle choices, environmental influences, or medical conditions, primary aging is unavoidable and affects individuals regardless of their health behaviors or surroundings. Understanding primary aging is essential for recognizing the distinct aspects of the aging process that are intrinsic to the biological aging timeline of all humans.