Headache on the side next to the ear may be trauma, migraine, otitis media and so on. 1. Trauma: This symptom may appear after the head is hit, squeezed, sharps injury, contusion and other traumatic injuries, resulting in scalp breakage on the injured side, subcutaneous hematoma or even skull and intracranial brain tissue injury. 2. Migraine: it may be related to heredity, mental and psychological disorders, metabolic disorders, etc. It is usually triggered by stress, lack of rest, strong sensory stimulation, etc., with throbbing pain on one side of the head. 3. Otitis media: bacterial infection causes inflammatory reaction in the middle ear, a large amount of inflammatory material secretion leads to increased pressure in the middle ear, and in severe cases, earache on the affected side and temporal pain in the head may occur. Headache on the side next to the ear may be related to a variety of factors, it is recommended to consult a doctor for a clear diagnosis.