A four-year-old girl’s beard growth may be caused by abnormal hormone levels, genetic factors, and the child’s oral intake of hormone-containing drugs. You can take the treatment of the original disease, stop using drugs and other methods of treatment to alleviate. 1. Abnormal hormone levels: If a four-year-old girl has too little estrogen or too much androgen secretion, it will cause the child to develop male sexual characteristics, and common diseases include Cushing’s syndrome. After treatment of the original disease, the child’s hormone levels will gradually return to normal, and the symptoms of beard growth will also improve. 2. Oral hormones: If a four-year-old girl takes oral hormones for a long time, it will lead to metabolic disorders in the child’s body, causing the child to grow a beard. After the hormones are reduced and stopped, the symptoms of beard growth will be reduced and disappear. 3. Genetic factors: the girl simply grows a beard, may also be due to genetic factors. In this case, observation is usually sufficient. If a four-year-old girl appears to have a long beard obviously, at the same time there are other uncomfortable symptoms such as breast development, etc., it is recommended to consult a doctor in a timely manner, under the guidance of the doctor, improve the relevant examination, clarify the cause of the disease, targeted treatment.