Hair transplantation is a common procedure in which hair follicles from the back of the head are removed, processed and transplanted to the desired area. After several months of survival, stable development and growth, normal hair can be grown. However, there are different degrees of hazards or risks in the process of hair transplantation, but there are not specific top ten hazards, the following are common: 1. damage to the scalp: because of the need to operate on the head, the head is distributed with a large number of nerves and blood vessels, if there is a mistake may cause some damage to the head tissue, bleeding, edema, etc.; 2. damage to the hair follicles: the surgery requires taking hair follicles in their own head This may lead to damage to the hair follicles at the site of hair extraction, which may affect the growth of hair and lead to hair loss or thinning of hair; 3. Hair transplants generally have less rejection reactions, but there will be some inflammatory reactions and local edema after the hair transplant. Allergic reactions may also occur and local itching may occur. In this case, you should avoid scratching, and you should not worry too much. You can use medication as prescribed by your doctor, or you can apply local cold compresses to relieve it. After the hair transplant, you need to pay attention to scalp hygiene to avoid infection.