What causes cluster headaches?

Unknown. No one really knows the cause but it is much more common in men where most heaches have a female proponderance the typical patient is a tall thin man who smokes!
Get it checked. Have you had any head trauma? Have you had a ct scan? Noninvasive osteopathic cranial treatments are the safest approach to the mechanical aspects of headache syndromes. Cranialacademy.Org has a doctor finder function.
Cluster Headache. The cause of Cluster Headache is unknown. The trigeminal-autonomic reflex pathway in the brainstem is activated. The trigeminal nerve is the chief sensory nerve of the face. The trigeminal nerve also stimulates parasympathetic autonomic system, which causes the eye tearing and redness, nasal congestion and discharge with cluster attacks.Cluster headaches appear to be generated by the hypothalamus.