There are many causes of headaches, and often it is a harmless condition. However, it is advisable to seek medical attention if the headache is very severe, suddenly worsens or recurs, if it is accompanied by other symptoms such as visual disturbances, speech or movement coordination disturbances, or if the headache prevents normal functioning. Also, if the headache does not respond to common pain relievers or if it wakes you up at night, you should consult a doctor.