Hypothyroidism, also known as hypothyroidism, may cause hair loss. Hypothyroidism is a generalized hypometabolic syndrome caused by insufficient production of thyroid hormone, or thyroid hormone resistance, due to various causes. Its pathology is characterized by the accumulation of mucopolysaccharides in the tissues and skin, causing the patient to have a mucous edema face, thickening of the nose and lips, a large and indistinct tongue, slow speech, dry, thinning and brittle hair, loss of eyelashes and eyebrows (especially at the tips of the eyebrows), and slow growth of the male beard. In addition, patients with hypothyroidism may also experience symptoms such as easy fatigue, fear of cold, weight gain, and slowness of movement. Patients need to be treated with medications such as levothyroxine tablets under the supervision of a doctor. Patients with hypothyroidism are advised to go to the hospital if they have symptoms of hair loss, so as not to delay their condition.