It is pain felt within the head, the site of which varies according to the cause of the headache. Headache is often a symptom of illness or disorder. It may be accompanied by other symptoms, such as nausea and vomiting.

Common causes are stress, tiredness, and feverishness accompanying an infection such as cold, an excess of intense work involving the eyes, indigestion and digestive disorders, over-exposure to sun, and hunger. Other serious causes like kidney failure, glaucoma, meningitis, and brain tumour, also cause headache. It is advisable to have a thorough medical check-up to rule out any serious problem in the body.