Hair transplantation is a more common and effective method for treating hair loss and baldness with high satisfaction. It mainly takes hair follicles from the patient’s hair growth area and transplants them to the hair thinning area. If improper operation in the hair transplantation process or if no care is taken after the hair transplantation, the following hazards can be caused: 1. Bleeding: Before the hair transplantation operation, necessary auxiliary examinations should be performed to assess whether the patient’s bleeding and coagulation functions are normal and whether there is thrombocytopenia, etc.; 2. Infection: If the doctor does not operate properly or the patient’s own condition is poor, infection can occur after the operation, producing anemia, hypoproteinemia and other malnutrition, or with diabetes, folliculitis, acne, etc.; 3, scalp discomfort: can be caused by the damage to the superficial sensory nerves during the surgery, generally after 0.5-2 years to alleviate; 4, scar: no matter what kind of surgery, there is a possibility of scar formation, if the patient is a scar body, should not be hair transplant. To sum up, in order to minimize the above hazards, it is recommended that before undergoing hair transplantation, candidates should be well prepared and choose professional institutions and experienced doctors for the operation.