Headache Headache Galil Category="Neurology"Category="Symptoms"A headache (medically known as cephalalgia) is a condition of mild to severe pain in the head; sometimes upper back or neck pain may also be interpreted as a headache. Headache is the second-most common form of local pain. (The most common is molar pain, i.e. Toothache in one or more of the flat-crowned teeth used for grinding food.)

Headaches have a wide variety of causes, ranging from eyestrain to inflammation of the Sinus cavities to life-threatening conditions such as Encephalitis, brain cancer, Meningitis, and cerebral aneurysms. When the headache occurs in conjunction with a Head injury the cause is usually quite evident; however, many causes of headaches are more elusive. The most common type of headache is a Tension headache. Some people experience headaches when they are hungry or dehydrated (severe dehydration is the cause of the headache during a Hangover, since Alcohol is a Diuretic).

It is common to take Over-the-counter painkillers such as Aspirin, Paracetamol or Ibuprofen to relieve headaches. However, when taken too frequently, painkiller medications may actually cause headaches.

Pathophysiology

The Brain tissue, the Dura mater and the Skull bones are not sensitive to Pain, because they lack pain-sensitive nerve fibers. Several areas of the head can hurt, including a network of nerves which extends over the scalp and certain nerves in the face, mouth, and throat. The basal part of the Meninges and the great blood vessels, arteriae as well as sinuses, do have pain perception. Headache often results from traction to or irritation of the meninges and blood vessels. Also sensitive to pain, are the muscles of the head.

The ends of these pain-sensitive nerves, called nociceptors, can be stimulated by stress, muscular tension, dilated blood vessels, and other triggers of headache. Once stimulated, a nociceptor sends a message up the length of the nerve fiber to the nerve cells in the brain, signaling that a part of the body hurts. The message is determined by the location of the nociceptor.

A number of chemicals help transmit pain-related information to the brain. Some of these chemicals are natural painkilling proteins called endorphins, Greek for "the morphine within." One theory suggests that people who suffer from severe headache and other types of chronic pain have lower levels of endorphins than people who are generally pain free.

Types

There are four types of headache: vascular, muscle contraction (tension), traction, and inflammatory. The most common type of vascular headache is migraine. Migraine headaches are usually characterized by severe pain on one or both sides of the head, an upset stomach, and, at times, disturbed vision. Women are more likely than men to have migraine headaches. After migraine, the most common type of vascular headache is the toxic headache produced by fever. Other kinds of vascular headaches include "cluster” headaches, which cause repeated episodes of intense pain, and headaches resulting from high blood pressure. Muscle contraction headaches appear to involve the tightening or tensing of facial and neck muscles. Traction and inflammatory headaches are symptoms of other disorders, ranging from stroke to sinus infection. Like other types of pain, headaches can serve as warning signals of more serious disorders. This is particularly true for headaches caused by inflammation, including those related to meningitis as well as those resulting from diseases of the sinuses, spine, neck, ears, and teeth.

Causes

There are many different causes of headache. They can be broadly classified in the following three categories:

Diagnosis

Headaches can serve as warning signals of more serious disorders. This is particularly true for headaches caused by traction or inflammation. When an underlying cause is suspected for the headache, further diagnostic tests will be done. A test called an electroencephalogram (EEG) may be given to measure brain activity. EEG's can indicate a malfunction in the brain, but they cannot usually pinpoint a problem that might be causing a headache. A physician may suggest that a patient with unusual headaches undergo a computed tomographic (CT) scan and/or a magnetic resonance imaging (MRI) scan. The scans enable the physician to distinguish, for example, between a bleeding blood vessel in the brain and a brain tumor, and are important diagnostic tools in cases of headache associated with brain lesions or other serious disease. CT scans produce X-ray images of the brain that show structures or variations in the density of different types of tissue. MRI scans use magnetic fields and radio waves to produce an image that provides information about the structure and biochemistry of the brain.

If an aneurysm-an abnormal ballooning of a blood vessel-is suspected, a physician may order a CT scan to examine for blood and then an angiogram. In this test, a special fluid which can be seen on an X-ray is injected into the patient and carried in the bloodstream to the brain to reveal any abnormalities in the blood vessels there.

Treatment

Not all headaches require medical attention. But some types of headache are signals of more serious disorders and call for prompt medical care. These include: sudden, severe headache or sudden headache associated with a stiff neck; headaches associated with fever, convulsions, or accompanied by confusion or loss of consciousness; headaches following a blow to the head, or associated with pain in the eye or ear; persistent headache in a person who was previously headache free; and recurring headache in children.

When headaches occur three or more times a month, preventive treatment is usually recommended. Drug therapy, biofeedback training, stress reduction, and elimination of certain foods from the diet are the most common methods of preventing and controlling migraine and other vascular headaches.

Types of headache

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