A pit in the top of the head may be congenital dysplasia, calcium deficiency, trauma, etc., and you should consult a doctor in time to find out the cause of the problem. 1. Congenital dysplasia: It is possible that the sleeping posture is incorrect, which leads to the unevenness of the top of the head with a pit, as long as there is no uncomfortable situation, generally do not need treatment. 2. Calcium deficiency: Calcium in the human body is an important substance for bone synthesis, and hypocalcemia can lead to bone dysplasia, thus causing a pit on the top of the head. 3. Trauma: after a car accident or a fall, the head hits the ground and there is a pit on the top of the head, with headache, vomiting and other symptoms. In addition to these factors, we can not rule out other causes, we recommend that patients seek medical attention to clarify the cause of the disease, and follow the doctor’s instructions for standardized treatment.