Cluster headaches

These are the most common symptoms of a cluster headache:

• Cluster headaches usually occur in a series that may last weeks or months.
• Severe pain on one side of the head, usually behind one eye
• The eye that is affected may be red and watery with a droopy lid and small pupil
• Swelling of the eyelid
• Runny nose or congestion
• Swelling of the forehead