Cluster headaches

[Kit]

A cluster headache causes severe pain that is felt at the temple or around the eye on one side of the head and that lasts a relatively short time (usually 30 minutes to 1 hour). It is accompanied by nasal congestion or a runny nose and sometimes a drooping eyelid, tearing, and a flushed face. Headaches usually occur regularly during a 1- to 3-month period, followed by a headache-free period of months to years.

Excruciating pain occurs on one side of the head, causing the nostril and the eye on that side to water.
People are often restless and pace.
Doctors base the diagnosis on symptoms.
Oxygen (given by a face mask) or drugs are needed to treat headaches.
Most people with cluster headaches need to take drugs to prevent attacks from recurring.

(See also Overview of Headache.)
Cluster headaches are relatively rare, affecting about 4 of 1000 people in the United States. Cluster headaches are more common among men. They typically begin between the ages of 20 and 40.

[Mark Zuckerberg]

a very severe headache, affecting mainly one side of the head and happening several times within a period of time: