Keratin is a protein. Hair contains 98% protein and 3% water. All we see in the hair is dead cells. Because there are no sensory cells in it. Our skin contains a type of cell called melanocyte , which produces melanin. People who produce less melanin have a whiter complexion and those who produce more melanin turn black. The same can be said for hair. If for some reason the melanocyte cells at the base of the hair become inactive and the production of melanin stops, the result is a white hair color which we call hair maturation. It can happen at any age. Studies have shown that this problem occurs in many people due to hereditary reasons . In some people who lose their hair at an early age, melanocyte cells become inactive due to autoimmune diseases. As a result, melanin does not reach the hair. This autoimmune disease produces anti-melanocyte antibodies against melanocytes in the skin , which destroy melanocyte cells. Studies have shown that high fevers , long-term illness and mental anxieties can cause hair loss at an early age. In addition, if the hair lacks enough protein, the hair begins to mature. Hair color pigment cells maintain the normal color of each hair from the beginning of the hair. But with age, the pigment cells in the hair begin to die and the hair color changes one by one. And in this way all the hair gradually changes from black to gray or completely white. The various hormones responsible for hair growth are secreted more when people are under more tension. And because of this, one's hair can get gray due to tension.