Black spots on the private parts and getting bigger, most of them are the symptoms of birthmarks, pigmented nevi, flat warts or Bowen-like papular disease. It is necessary to go to the hospital in time, after a clear diagnosis, according to the doctor’s prescription medication. 1. Birthmarks are caused by abnormal differentiation of skin tissues during embryonic period and can appear in any part of the body. It can appear in any part of the body. It is manifested as a black spot or black spot on the genitals, which will increase in size as the body grows, and will no longer grow in adulthood, and has no effect on the body, usually with no self-conscious symptoms. 2. Pigmented nevus is a kind of benign skin growth, the cause of which is unknown, and it can appear in any part of the body. It can appear as a black spot or black pimple on the vulva, which can grow slowly without any obvious symptoms of self-consciousness, and it is recommended to remove the nevus from the friction area. 3. Flat warts are caused by viral infections and are transmitted through skin-to-skin contact. It is a very good way to get the most out of your life, and it is a very good way to get the most out of your life. 4. Bowen-like papulosis is related to HPV16 (human papillomavirus-16) infection, and sexually active young men and women are prone to have it. The manifestation is one or more brown or black soft bumps appearing on the skin, the bumps can gradually increase, but most of them can subside on their own, and there is often hyperpigmentation after subsiding. There may be other reasons for the appearance of the above situation, it is recommended to go to the hospital in a timely manner, to clarify the cause of the disease, symptomatic treatment.