Life expectancy increased dramatically in the twentieth century. Continued gains in life expectancy are not guaranteed. Physical and Biological Aspects of Aging Aging-related physical change is not as important as we once thought. Physical aging is an inevitable, multifaceted process. Physical aging is a slow, gradual, life-long process.
Most living things have life cycles of patterned biological changes.
Disabilities, sensory loss, and chronic diseases increase with age but are not inevitable aging conditions. The rate of physical aging among humans varies widely. Sexuality is a characteristic of people at all ages. Death and disability can occur at any age. Most older adults maintain active, independent lives.