Hair yellow, dry and frizzy may be related to hypothyroidism, micronutrient deficiencies, malnutrition, patients should go to the hospital dermatology department to diagnose and clarify the cause of the disease by taking medication, iron supplements, protein supplements, etc. to improve. 1. Hypothyroidism: if the patient examination found that the hair is yellow and dry, and hypothyroidism and other endocrine diseases related to patients need to actively treat hypothyroidism, alleviate the symptoms, usually follow the doctor’s instructions to take thyroxine for treatment. 2. Lack of trace elements: some patients with yellow hair and dry hair lack of iron and copper and other trace elements related to the patient can be appropriate supplementation of ferrous sulfate to improve the symptoms, but also intake of animal liver, meat, milk and eggs and other foods. 3. malnutrition: long-term malnutrition is also easy to cause hair protein deficiency makes hair yellow and dry, patients can usually appropriate intake of peanuts, soy, eggs, black sesame and other foods containing animal protein and vegetable protein to ease the hair yellow and dry. Hair yellow and dry may also be related to hair dehydration, patients usually pay attention to protect the hair, avoid hair by high temperature stimulation and sun exposure. If necessary, it is recommended to go to the hospital, after the disease is clarified in the doctor’s guidance to treat the symptoms.