A headache is a condition wherein the sufferer develops an uncontrollable compulsion to YELL EXPLETIVES VERY LOUDLY. If you or someone you know has a headache, be sure to stay away from teenage vampires making out , as the combination of rage and the predisposition for yelling may make the vampires cry tears of blood.
A form of this condition may be developed by reading bad fanfiction, such as My Immortal. A milder form may be developed by reading descriptions of the same bad fanfiction. If there is a reason why either must be done, it is recommended that ibuprofen or aspirin be kept near the reader's computer, in case of emergency.
Other effects of this condition may include: insanity, destructive impulses, insomnia, and a strong desire for Brain Bleach.