More than 300 known medical disorders can produce headaches. Primary headaches include migraine, tension-type and cluster headache. Furthermore, about 90% of the people who see a doctor for headaches will generally have one of the above mentioned types of headaches. Primarily, headaches are considered to be harmless, but there recurrence can be an issue for many people.

Tension headaches are further divided into episodic or chronic with the presence or absence of pericranial muscle tenderness (pain on the outside of the skull).

People with episodic tension-type headaches will normally have a history of at least 10 previous headache episodes lasting from 30 minutes to 7 days but occurring fewer than 180 times a year. This type of headache must have at least two of the following characteristics like:

Pressing/tightening (non-pulsating) quality, located on both sides of the head

Mild or moderate intensity

Not aggravated by routine physical activity

No nausea or vomiting

Possible sensitivity to light or sound but not both

People with chronic tension-type headache have an average headache frequency of 15 days a month or 180 days a year for 6 months. In addition, these people must also meet the criteria for episodic tension-type headache. Moreover, people suffering from chronic tension-type headache must not be suffering from another disorder that is easily detected by a physical and neurological examination.

Diagnosis of most tension-type headaches, are based on a person's medical history as well as a complete and comprehensive physical examination. It is understood that no further diagnostic studies are needed for these people who present with normal neurological examination findings and are otherwise healthy.

On the contrary, people with chronic tension-type headache, must undergo a CT scan and an MRI, regardless of what their neurological examination findings are. Although this medically advanced imaging may rarely help in diagnosing a specific type of headache syndrome, it may definitely prove invaluable in excluding other causes of headaches. Moreover, it is essential that tests like thyroid function studies, complete blood cell count, and metabolic screening also be performed to ascertain the cause of the headache.

The onset of tension-type headaches is generally associated with stress or upsetting emotional situations. However, studies involving these factors have not been shown to lead to muscle contraction or reduced blood flow to the head. Nonetheless, people may suffer from tenderness of the muscles surrounding the head region. Therefore, it can safely be assumed that tension-type headaches are not a result of sustained muscle contraction.

According to existing evidence, which is also the most convincing; deliberation of the issue has led the researchers to conclude that a central nervous system dysfunction is the underlying cause of most tension-type headaches. As a consequence, muscle aches during tension-type headaches are thought to be a result of increased sensitivity of the nervous system. Moreover, these muscle pains are a result of occasional or long-term imbalances in brain chemicals known as neurotransmitters (serotonin, dopamine, norepinephrine, enkephalins).

Studies have revealed that some people with primary headache disorders may respond to medications that are designed to specifically target and influence serotonin levels in the brain. Positive response is generally seen in people suffering primarily from migraines or cluster headaches. On the contrary, people who are not afflicted with migraine or cluster headache do not respond positively to serotonin-targeted drugs.

Similarly, there is a possibility that people with chronic tension-type headaches may also have neurochemical imbalances in their body. In fact, depression may also be an essential factor in a certain number of people with chronic tension headaches. Furthermore, sleep disorders could also be linked to serotonin depletion.

Prescription-strength pain relievers may be given once the doctor has a better understanding of a person's headache as well as the various other coexisting medical conditions that a patient may present with. However, care must be taken to prevent people from becoming dependent on strong narcotic drugs, especially when headaches are not a one-time thing but tend to recur at regular intervals.

For headaches, doctors may first prescribe pain relievers like:

Nonsteroidal anti-inflammatory drugs (NSAIDs)

Triptans

Ergots

Anti-nausea medications

Butalbital combinations

Opiates

However, pain that cannot be controlled with pain relievers, doctors may prescribe preventive therapy such as:

Cardiovascular drugs (Beta blockers, Calcium channel blockers and antihypertensive drugs)

Antidepressants

Anti-seizure drugs

Cyproheptadine

Botulinum toxin type A (Botox)