Aging is a highly individualized matter. There is no single measure of how "old" a person is. Aging proceeds at different rates in different people and at various rates in various systems of the same person.

There are several theories that account for the physical changes coming with age, but none explain adequately why these changes take place. The physical changes are mainly due to the slower replacement of worn out cells, so that the body is unable to maintain complete and optimal functioning. The brain is affected by the diminished production of its chemical communicators, decreased circulation and less accurate sensory perception, so that it takes a little longer to process new information and react to different stimuli. However, in spite of this slowing down, there is no overall loss of mental functioning or intelligence.

The physical changes that accompany aging are not necessarily incapacitating, even though they may be discomforting or limiting. The body has less s

The use of eyeglasses may become necessary, even if they were not necessary earlier in life. Old people can hear low tones fairly well, but their ability to hear high tones decreases. The capacity of tissue and bone to repair itself is slowed, as is cellular growth and division. Bones become brittle and skin loses its thickness and elasticity, causing wrinkles. As brain cells die some capacity for memorization and learning is lost. Breathing becomes difficult and hardening arteries circulation to worsen and blood pressure to rise. Joints lose their mobility and deteriorate from constant wear and pressure. Finally, the liver filters toxins from the blood less efficiently. These are not all of the changes to the body that are brought about by aging, but these are the major ones. There is hope in modern medicine, though. Through the use of new technologies and drugs some of these changes can be slowed or prevented.

Some topics in this essay:
BRAIN/NERVOUS SYSTEM, Nutrient Requirements, Physical Changes, Elimination System, Environmental Delirium, Sense Touch, Nutrient Deficiencies, , Folate Folate, Teeth Mouth, -process accelerated, body weight, physical changes, elderly people, heart disease, common causes •, • people, total calories/day, vitamin deficiency, causes •, †elderly, -process accelerated smoking, ability heart pump, organic mental syndrome, accelerated insufficient exercise,