Starting to grow gray hair at the age of 32 may be caused by physiological factors such as overwork, mental tension and stress, or it may be caused by diseases such as vitiligo. 1. Physiological factors: if you are often overworked, or in a state of long-term mental tension and stress, it may lead to start growing gray hair at the age of 32. 2. Vitiligo: the cause of the disease may be related to autoimmune abnormalities, heredity and other factors, mental factors, skin injuries and other reasons may also induce the disease. The patient will be localized in the size of the white spots, can be seen in the whole body, head and face vitiligo may lead to long white hair. There are more reasons why people start to grow gray hair at the age of 32. After excluding physiological factors, it is recommended to go to regular hospitals for examination and clarification of the cause of the disease.