A headache after running may be due to a transient headache caused by strenuous exercise, or it may be secondary to high blood pressure, migraine and other diseases. 1. Strenuous exercise: running is too strenuous or lasts too long, which can lead to dehydration, hypoglycemia and other symptoms, and then cerebral vasodilatation, thus causing headaches. 2. Secondary to hypertension: exercise can induce headaches in hypertensive patients, mainly due to increased intracranial pressure, resulting in headache symptoms. 3. Migraine: a part of migraine patients can be induced by exercise, thus headache. When the symptoms of dizziness and headache appear after exercise, you should go to the regular hospital, clarify the cause of the disease and carry out treatment under the guidance of the doctor.