There are numerous reasons why 35 year olds have more gray hair, mainly genetic factors, environmental factors and disease factors. 1. Genetic factors: If a person with a lot of gray hair at the age of 35 has his own parents with a history of teenage whiteheads, then it is very likely to be caused by genetic factors. 2. environmental factors: if the work pressure is large or often stay up late and so on, then it is very likely to appear 35 years old gray hair much situation. 3. Disease factors: vitiligo and baldness and other skin diseases, may also produce white hair and other manifestations; endocrine diseases can also cause white hair, such as pituitary lesions and hyperthyroidism and other diseases can be caused by the impact of pigment cells white hair. The 35-year-old gray hair need to go to the hospital in time, under the guidance of the doctor for professional diagnosis and treatment.