Conditions InDepth: Headache
Headache refers to head pain (cephalgia). There are several different types of headache, including:
Headaches may also have other causes, such as:
- Side effects of medicines
- Overuse of medications to treat headaches
- Head injury
- Increased pressure in the head
While the precise cause of many headaches remains unknown, several theories exist. The causes of a headache vary depending on the type of headache.
refers to head pain associated with stress and muscle contraction. These headaches may occur only occasionally in response to a stressful event. They may also be chronic, occurring frequently. Some tension headaches are nearly constant, with daily pain that may vary in intensity. Tension headaches occur when muscles in the neck, face, and scalp contract and produce pain. The precise cause of this muscle contraction is unknown, but stress,
depression, eyestrain, and other factors may contribute.
is a type of recurring headache that involves blood vessels, nerves, and brain chemicals. Sensations such as visual changes, called auras, may precede a migraine. The International Headache Society has a system that classifies migraines as one of two types: migraine occurring with an aura and migraine occurring without an aura.
Migraines may occur several times a week or once every couple of years. Migraines may be so severe that they interfere with your ability to work and carry on normal activities.
An internal or external trigger sets off a process that results in migraine headaches. The exact trigger is often unknown. It is possible that the nervous system reacts to the trigger by conducting electrical activity that spreads across the brain. It leads to the release of brain chemicals, which help regulate pain.
is a type of severe, recurring pain that is located on one side of the head. It received its name from the clustering or pattern of frequent headaches that usually occur.
There are 2 main types of cluster headaches. Either type of headache may convert to the other type:
- Episodic cluster headaches—(80% of all cases) occur one or more times daily for several months. The headaches then enter a period of remission and come back months or years later.
- Chronic cluster headaches—(20% of all cases) occur almost daily with, at most, one headache-free month during a year.
The cause of cluster headaches is unknown.
are associated with inflammation of the sinuses (called
sinusitis). The sinuses are hollow cavities in the skull. Colds and allergies cause inflammation of the nasal passages and can lead to sinusitis. Allergies and viral upper respiratory infections increase nasal secretions and cause tissue lining the nasal passages to swell. This results in nasal congestion and stuffiness. The nasal passages become blocked and normal drainage cannot occur. Secretions that are trapped in the sinuses may become infected with bacteria or, rarely, fungus. The swollen tissues or infection may create pain and pressure.
What are the risk factors for headaches?
What are the symptoms of headaches?
How are headaches diagnosed?
What are the treatments for headaches?
Are there screening tests for headaches?
How can I reduce my risk of getting headaches?
What questions should I ask my doctor?
What is it like to live with migraine headaches?
Where can I get more information about headaches?
Cluster headache. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T116292/Cluster-headache. Updated February 16, 2016. Accessed September 30, 2016.
Headache. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T114773/Headache. Updated August 9, 2016. Accessed September 30, 2016.
Headache—frequently asked questions. National Headache Foundation website. Available at:
http://www.headaches.org/headache-faq. Accessed November 7, 2012.
Migraine in adults. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T114718/Migraine-in-adults. Updated June 24, 2016. Accessed September 30, 2016.
NINDS headache information page. National Institute of Neurological Disorders and Stroke
website. Available at:
http://www.ninds.nih.gov/disorders/headache/headache.htm. Updated September 2012. Accessed November 7, 2012.
Tension-type headache. EBSCO DynaMed website. Available at: http://www.dynamed.com/topics/dmp~AN~T114522/Tension-type-headache. Updated September 15, 2016. Accessed September 30, 2016.