A: The most important cause of hair loss is heredity. Men and women inherit the hair loss genes from either or both parents. In genetically susceptible men, the hormone Dihydrotestosterone causes a gradual miniaturization and eventual hair loss. While in the female the causes are not very clear. The onset age, extent, and speed of hair loss vary from person to person. Male and female exhibit hereditary hair loss differently. Prolong and severe illness, medications, malnutrition, or vitamin deficiency can speed up this process. Incorrectly applied, permanent hair colour, gel, and chemical relaxers also damage the hair permanently. Wearing a hat or helmet, shampooing or clogged pores has no role in hair loss.