Suddenly a small patch of hair goes bald, the medical name for this is baldness. It can heal on its own in milder cases, while stubborn baldness usually requires medication. The occurrence of baldness is often due to a number of factors such as poor rest, lack of sleep, and stress, resulting in hair loss in restricted areas. Most of this disease can heal on its own, but some patients with more severe cases cannot heal on their own and must be treated systematically in a dermatology department. It takes a long time to heal, usually about 0.5-1 year. During the recovery period, patients should take rest, sleep and avoid too much mental stress. Patients with persistent baldness can apply topical minoxidil rub or local injection of lidocaine with dexamethasone to relieve the condition. The treatment of baldness takes a long time and is prone to recurrence. Patients can eat more hair nourishing and protective foods in their daily life, such as black sesame and black rice.