Hair turning gray in large quantities at the age of 35 may be caused by heredity, mental stress, disease causes, drug factors and so on. 1. Heredity: genetic inheritance can lead to teenage gray hair, at the age of 35, the hair will be a lot of white, usually no conscious symptoms, which has a certain relationship with the lack of melanin. 2. Mental stress: prolonged mental stress can lead to endocrine disorders, making melanin deficiency, causing hair to turn gray. 3. Disease: Melanin is produced by melanocytes, which is an important determinant of skin color. If melanocytes are destroyed, it will lead to melanin production disorders with white hair, and vitiligo will make the skin white, and may also lead to local hair white. In addition, some endocrine diseases will accelerate the aging of melanin production, such as early onset ovarian insufficiency, male androgen reduction and so on, resulting in a large number of hair white. 4. drug factors: tyrosinase function abnormalities will have an impact on melanin formation, if due to some diseases require the use of tyrosine kinase inhibitors will inhibit normal cell growth, accelerate cell apoptosis, affecting the function of the hair follicle, resulting in a large number of gray hair. 35 years old hair a lot of white should go to the hospital dermatology consultation, clear cause symptomatic treatment.