What are cluster headaches?
Cluster headaches are severe headaches on one side of your head that happen in groups, or "clusters." They usually occur over weeks or months.
Cluster headaches can be so painful that you are not able to follow your normal routine or do your usual activities. The pain is often called the worst type of headache pain.
Cluster headaches come in cycles (also called cluster periods). Most people who get cluster headaches have one or two cluster periods each year. A cluster period might last 1 month or longer. After a cluster period ends, you may not get another headache for months or even years.
As you get older, it's likely that you'll have longer and longer times without headaches. At some point, you may not get cluster headaches ever again.
Having cluster headaches can be scary. But even though they are very painful, cluster headaches don't cause long-term harm. During a cycle, you may be able to reduce how often you have them, how bad they are, and how long they last.
What causes cluster headaches?
Experts aren't sure what causes cluster headaches. They run in families, but it's not clear why some people get cluster headaches and others don't.
What are the symptoms?
The main symptom of cluster headaches is a severe burning or sharp, piercing pain on one side of your head. The pain spreads out from your temple and eye. Your eye may become red, watery, or puffy. The eyelid may droop, and you may have a runny or stuffy nose on that side of your head.
See a picture of cluster headache symptoms .
The pain usually gets bad very fast. The pain gets worse within 5 to 10 minutes after the headache starts and can last for 15 minutes or longer.
Cluster headaches usually happen at the same time of day each time you get them. But they can happen at any time. You may have 1 to 8 headaches a day.
How are cluster headaches diagnosed?
A doctor can usually tell if you have cluster headaches by asking about your symptoms and examining you. Your doctor may order other tests, such as a CT scan or an MRI, if he or she thinks your symptoms are caused by another disease. But most people won't need these tests.