What Is a Headache?
What Is a Headache?
January 05, 2009
By Mark Foley, D.O.

A headache is pain that occurs in the head and upper neck region of the body. It can affect a small portion of the head, such as the eyes or temples, or it can affect the entire head. The pain may be sharp or dull, and may come along with a variety of other symptoms like light sensitivity or nausea. Whatever the specifics may be, headaches are extremely common. About seven out of 10 Americans will have one this year. Over 45 million people in the United States suffer from chronic headaches, which are headaches that return with some frequency.

Headache symptoms can vary between different people, but there are three main types: tension headaches, migraine headaches, and cluster headaches.

Tension Headaches

Tension headaches tend to feel like a tightening around the head. These types of headaches were once thought to be associated with stress or poor posture, resulting in tightness of the muscles of the head and neck. It is difficult to determine with certainty what causes headaches since there are many factors to consider. Women are more likely to develop tension headaches than men. But most adults between ages 20 to 50 will have at least one tension headache in their lifetime.

Migraine Headache

Migraine headaches are usually intense and throbbing, often involving one side of the head, although they can affect the entire head. As is the case for tension headaches, the cause of migraine headaches is still being researched. There is some thought that an imbalance in the nervous system, especially in the trigeminal nerve, may trigger dilation and inflammation of blood vessels in the head. This dilation and inflammation is responsible for the pain experienced during a migraine. Many times, they are associated with light or sound sensitivity (photophobia and phonophobia), and occasionally with nausea and vomiting. Women are nearly three times more likely to have a migraine than men, with 17 of women experiencing a migraine during their lifetime. Migraine headaches can occur with or without an aura, a group of symptoms that occur before a headache starts.

Cluster Headache

Cluster headaches are far less common than other types of headaches and, unlike migraines and tension headaches, affect men more than women. Altered blood flow in the blood vessels of the head and involvement of the trigeminal nerve are two possible causes of cluster headaches, but the true cause is not yet clear to researchers. The pain is typically a sharp, stabbing pain located behind one of the eyes. The pain associated with a cluster headache usually lasts 30 to 45 minutes and crescendos toward the end of the episode.

Other Headaches

Occasionally headaches may be caused by a more serious medical condition. A severe headache associated with fever could indicate meningitis, or an infection of the tissues surrounding the brain and spinal cord. In the elderly, a headache accompanied by tenderness of the temple and scalp could be a sign of temporal arteritis, inflammation of a major artery of the scalp. In any case, a headache lasting over 24 hours or associated with severe symptoms, such as vomiting or visual changes, should be reported to a healthcare professional for further evaluation.


Cluster Headache. Worldwide Cluster Headache Support Group. Retrieved: August 21, 2008. http://www.clusterheadaches.com/about.html

Headache. American College of Physicians. Retrieved: August 18, 2008. http://www.acponline.org/patients_families/diseases_conditions/headaches/

NINDS Headache Information Page. National Institute of Neurological Disorders and Stroke website. Retrieved: August 19, 2008. http://www.ninds.nih.gov/disorders/headache/headache.htm

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