The body has less strength and less endurance as it ages, and needs more repair work. Its speed of reaction and its agility are slowed. The basal metabolism, or rate of energy production in the body cells, is gradually lowered, so that people tire more easily, and are more sensitive to weather changes. Sexual desire and ability decline although they need never entirely end for either sex. Hearing changes also come with greater age.
Older people hear low tones fairly well, but their ability to perceive the high tones declines.
The capacity of tissue and bone to repair itself is slowed, as is cellular growth and division. Bones are more brittle. Skin becomes drier and loses some of its elasticity. Artificial teeth may become necessary. Much of the disability and discomfort that used to be considered a part of normal aging can now be delayed with proper medical care and health habits.