Leukodystrophy is the whitening of hair due to pigment deficiency in the hair shaft, which can involve part of the hair or all of the hair. The mechanism involves impaired melanin synthesis, impaired melanosome formation, impaired melanosome transport, and impaired migration and survival of melanocytes. It can be divided into two categories: physiological gray hair and pathological gray hair. Aging gray hair is physiological gray hair, which is caused by the decay of melanin stem cell function, and the hair becomes gray or white with age. The hair often starts to turn white at the temples and gradually increases. The age, extent and degree of its occurrence vary greatly between individuals and may be related to genetic, nutritional, mental and environmental factors. Because senile gray hair is one of the manifestations of cellular and individual aging, attempts to reverse aging are extremely challenging. Some biological agents have been reported to promote melanin stem cell division and proliferation and melanin synthesis, and herbal components and physical therapy also have some effect, but the therapeutic effect needs further confirmation. Early graying (juvenile graying) often has a family history of inheritance and manifests as autosomal dominant inheritance. In addition to genetic factors there are often acquired factors such as psychiatric, drug, nutritional, and systemic diseases involved, and there is no definitive and effective treatment available. Congenital gray hair is usually present at birth or appears during childhood. It is often seen in genetic disorders such as albinism, mottled disease, Waardenburg syndrome, etc. There is also no effective treatment available. In addition, certain acquired skin diseases, such as vitiligo, can also cause whitening of the hair at the site of the white spots. Chronic wasting diseases such as diabetes can also lead to acquired gray hair, and the principle of treatment requires active treatment of the original disease. At present, there is no food or medicine that can turn gray hair into black hair except for hair dyeing, and long-term hair dyeing will have certain effects on the health of the hair and body. Friends with gray hair problems, do not believe in false propaganda, blindly and indiscriminately supplement. Keeping a relaxed mood, regular work and rest, balanced diet and proper exercise can reduce the production of acquired gray hair to some extent.