Baby gnawing nails, consider and psychological tension, zinc deficiency, iron deficiency anemia and other factors related. 1. Psychological tension: If the baby is anxious or depressed in his daily life, he will gnaw his nails to relieve the psychological pressure. 2. Zinc deficiency: if the baby’s body lacks zinc, it will also cause the symptoms of nail chewing, accompanied by loss of taste, decreased appetite, skin and mucous membrane barrier damage and other symptoms. 3. Iron deficiency anemia: when the baby suffers from iron deficiency anemia, it will trigger xenophagia, which will lead to nail gnawing symptoms. Baby nibbling nails, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.