The usual causes of pubic hair loss include low androgen levels, seborrheic dermatitis, and nutritional loss during menstruation. 1. Low levels of androgen: Androgen can help maintain the growth and health of hair, if the long-term use of oral contraceptives and other reasons lead to low levels of androgen in the body, it is easy to cause less pubic hair, and even the hair and armpit hair will become less. 2. Seborrheic dermatitis: If seborrheic dermatitis occurs repeatedly in the pubic area, it will cause localized itching and pain in the pubic area. If the itching is unbearable, the patient keeps scratching with his hands, which will result in less and less pubic hair. 3. Nutritional loss during menstruation: women will lose nutrients very quickly during menstruation, and if they can’t get nutritional supplements, it will result in poor physical condition, decreased resistance, less body hair, thinness and fatigue, etc., and it may also cause other complications and diseases. Therefore, if you find that your pubic hair has suddenly become less, it is recommended to go to the hospital for further examination and treatment to clarify its specific causes.