Hair transplantation is to take healthy hair follicles from the back and sides of the occipital area where hair growth is vigorous and transplant them into the area where hair loss occurs. However, if the incision has abnormal redness, swelling or bleeding, you need to contact the doctor for follow-up treatment in time; 2, infection: if the post-operative care is not proper, local skin infection may occur, which can be treated with antibiotics; 3, scar: for patients who choose FUT hair transplant, a thin scar will be left after the suture of the scalp strip is cut, but it is generally invisible when the hair is covered; for patients who choose FUE hair transplant, a white dotted scar will be left after the operation. The white dotted scar will be left after the surgery. If the patient is a keloid, it is recommended to avoid such invasive operations; 4. Granuloma: Since hair is a foreign body, if the hair follicle is not handled properly, it is easy to produce local granuloma-like reaction, but it can be removed by laser after the operation; 5. Superficial sensory nerve damage: Since hair transplantation requires punching holes in the donor and recipient areas, it can cause superficial sensory nerve damage, which is manifested as head discomfort, but this damage can be repaired by itself after six months to a year. 6.Hair does not survive after transplantation: the hair cannot grow after transplantation for various reasons, in general, the survival rate of transplanted hair follicles is about 90%.