A headache is when your head hurts. It is not when you hit your head with something and made it hurt that way, but when your head hurts from inside.
A headache can be caused by one of several things, which are listed here:
- Fever
- Watching television or looking at a computer screen for a long time.
- Being tired or sleepy.
- As an effect of stress
- By other neurological conditions ('neurological' means touching the nerves and the brain), like with epilepsy
The second edition of the International Headache Classification (ICHD-2) defines more than 220 different types of headaches in three categories:
- Primary headaches, for example migraine, tension headache and cluster headache.
- Secondary headaches
- Cranial neuralgias, central and primary facial pain and other headaches
Many headaches can be relieved with analgesics like aspirin.