Headache, Cluster - Cluster headache, also known as histamine headache, is a specific vascular headache syndrome. Attacks usually are severe and unilateral and typically are located at the temple and periorbital region. Each headache is brief in duration, typically lasting a few moments to 2 hours. Cluster refers to a grouping of headaches, usually over a period of several weeks.

At one time or another, almost everyone has had a headache. Some headaches are only moderately painful, while others are severe and disabling. No matter what kind of headache you have, you'd rather be without it.

In most cases headache pain, even severe headache pain, is not the result of any underlying disease. In fact, the vast majority of headaches are primary headaches - headaches that aren't caused by a specific medical condition. These include migraines, tension-type headaches and cluster headaches.

When to seek medical advice

Headache pain, even when severe, usually isn't the result of an underlying disease. Occasionally, however, headaches may indicate a serious underlying medical condition, such as a brain tumor or rupture of a weakened blood vessel (aneurysm). Be sure to tell your doctor about any headache that concerns you. If you have a history of headaches, see your doctor if the pattern changes or your headaches suddenly feel different.

• Brain tumor

• Encephalitis

• Meningitis

In addition, see your doctor or go to the emergency room immediately if you have any of these signs and symptoms:

• Abrupt, severe headache, often like a thunderclap

• Headache with a fever, stiff neck, rash, mental confusion, seizures, double vision, weakness, numbness or speaking difficulties, which may indicate a number of problems, including stroke, meningitis, encephalitis or brain tumor

• Headache after a head injury, even if it's a minor fall or bump, especially if it gets worse

• Chronic, progressive headache that worsens after coughing, exertion, straining or a sudden movement

• Onset of new headache pain after age 40

Call your doctor if your child has head pain that's severe or that causes him or her to miss school or other activities. Children who are too young to tell you what's wrong may cry and hold their heads to indicate severe pain.

• Encephalitis

• Meningitis

• Stroke