It is the number of pigment particles in hair that determines the color of hair, which is related to the development and growth of pigment cells in the papilla of hair roots. Hair turns from black to white. Generally speaking, the function of pigment cells in hair decreases. When it drops to the point where it can't produce pigment particles at all, the hair turns completely white. Normal people began to decline at the age of 35. And some people are white at the age of 20. In medicine, they are called juvenile white hair, commonly known as "juvenile white head".
The causes of baldness are complicated, which are related to both genetic and physical factors, as well as various acquired factors.
Baldness the day after tomorrow. There are many reasons: malnutrition, such as lack of protein, vitamins and some trace elements (such as copper), will make hair turn white; Some chronic consumptive diseases such as tuberculosis. Due to lack of nutrition, hair turns white earlier than ordinary people; Some patients with long-term fever, hair will turn yellow and brittle or even white and fall off; Some endocrine diseases, such as pituitary or thyroid diseases, will affect the ability of pigment cells to produce pigment particles, leading to premature whitening of hair; Encephalitis, neuropathy, etc. It can also make hair white; The skin, hair and eyebrows of albinos are all white; The disease of skin whitening-"vitiligo", if it happens on the scalp, the hair will also turn white; Others believe that the more you use your brain, the faster your hair will turn white; Some young people's hair turns white in a short time, which is related to severe mental trauma or mental fatigue such as excessive anxiety and sadness.