Swimming headache may be related to cold stimulation, may also be due to insufficient cerebral blood supply, high blood pressure and other reasons. 1. Cold stimulation: if the water temperature is low during swimming, the stimulation of cold water is likely to lead to capillary contraction of the head, which may cause headache, accompanied by head tightness, dizziness and other symptoms. 2. Insufficient cerebral blood supply: atherosclerosis, cerebral vascular stenosis patients, if the swimming time is too long, it is likely to cause the relative blood supply of brain tissue is insufficient, it may show headache symptoms, may also be accompanied by dizziness, weakness and other manifestations. 3. Hypertension: swimming because of the cold stimulation and exercise and other factors can lead to increased blood pressure, the original hypertension patients with basic diseases, due to increased blood pressure can appear headache symptoms. Swimming headache, may also be caused by other reasons, if the symptoms continue to be unable to alleviate, should seek medical attention as soon as possible, after diagnosis of the cause of the disease, to give targeted treatment.