Everyone grows older with each passing year. Every man in this world wishes to live long and nobody wants to grow old. But this desire of man is never fulfilled. Growing old is a natural process that begins with birth itself and continues throughout the life. As a man grows older, biological changes take place in his body. These changes can neither be prevented nor reversed. Old age is the culmination of these biological changes. Do you know which are the biological changes brought about by old age? The biological processes in a child’s body are much faster than those taking place in the body of an older person. As the biological processes slow down, the strength and sensitivity of man also diminish. This is because of the fact that the rate of production of proteins in the body decreases. Changes in the enzymes are also responsible for the aging process. With reduced physical activity, man starts losing weight; his eyesight becomes weak and his hair greys, thins out and he often becomes completely bald. All these are signs of old age. In the old age, changes occur in all the cells and tissues of the body. The cells of the kidneys, liver and intestines become weak. Blood vessels become old and consequently they are not able to carry blood and other nutrients adequately to all parts of the body. As a result, the process of aging is accelerated. As age advances, the eyes, ears, skin, teeth and digestion, all become weaker. Blood circulation becomes irregular. Various organs start malfunctioning. Finally, life comes to an end. The rate of growing old may be different in different people but old age spares none. This is a definite biological change, which cannot be prevented. However, with the help of nutritious food, clean environment and proper exercises, the deleterious effects of old age can be mitigated to some extent.