The sweat- and oil-secreting glands atrophy, depriving the skin of their protective water-lipid emulsions. The skin's ability to retain moisture then diminishes and it becomes dry and scaly.

Frown lines (those between the eyebrows) and crow's feet (lines that radiate from the corners of the eyes) appear to develop because of permanent small muscle contractions. Habitual facial expressions also form characteristic lines.

Gravity exacerbates the situation, contributing to the formation of jowls and drooping eyelids. (Eyebrows, surprisingly, move up as a person ages, possibly because of forehead wrinkles.)

In addition, the ability of the skin to repair itself diminishes with age, so wounds are slower to heal.