The evaluation of cluster headaches begins with a medical history and physical examination.

The physical examination is usually normal.

Physical findings that may occur during a cluster headache include:

• Conjunctival injection (red eyes)
• Eyelid swelling
• Facial flushing
• Facial sweating
• Watery eyes
• Constricted pupils
• Nasal congestion
• Drooping eyelid
• Runny nose

To make the diagnosis of cluster headaches, there should be at least 5 clustered attacks of severe, one-sided pain around an eye. The headaches must last from 15-180 minutes.

There are no specific tests that confirm the diagnosis of cluster headaches. Tests may be performed to exclude other causes for headache.

Tests that may be used to evaluate cluster headaches include:

• Complete blood count
• Spinal tap
• CT scanning of the brain
• MRI scan of the brain
• Sinus x-rays