Scarring alopecia cannot be regenerated, while seborrheic dermatitis, resting alopecia, and post-chemotherapy alopecia can still be regenerated. Whether hair loss can be regenerated or not is related to the cause of the hair loss. In the case of baldness caused by psychological or autoimmune factors, most patients are able to regrow after removing the cause. Seborrheic alopecia, also known as androgenetic alopecia, also has the possibility of regrowth if standardized treatment is given early in its development. However, severe seborrheic alopecia is more difficult to treat and regrowth is less likely. Hair loss caused by the toxic effects of chemotherapy drugs can be regenerated after stopping the drugs. In the case of alopecia areata and lupus erythematosus, the hair follicle structure has been permanently damaged and the hair cannot be regenerated. Patients with alopecia areata should go to the endocrinology department of the hospital for early examination and early treatment, the possibility of hair regeneration is greater, the later the treatment, the worse the prognosis.