The yellowing of hair may be caused by genetic factors, malnutrition, lack of trace elements, improper care and other reasons. 1. Genetic factors:The yellowing of hair is mainly related to genetic factors. 2. Malnutrition:Dietary structure or some major diseases caused by malnutrition, will directly affect the supply of nutrients to the hair, so that the hair due to a lack of nutrients and yellowing. 3. Lack of trace elements: the lack of trace elements in the body will also have a direct impact on the color of the hair, including copper, zinc, calcium and other trace elements have a great impact on the color of the hair. 4. Improper care: the long-term use of some substandard quality shampoo, will cause damage to the hair, so that the hair yellow, forked. Symptoms of yellowing hair should go to the hospital in time and be treated under the guidance of the doctor.