Headache is pain in any region of the head. Headaches may occur on one or both sides of the head, be isolated to a certain location, radiate across the head from one point, or have a vise-like quality. A headache may be a sharp pain, throbbing sensation or dull ache. Headaches may appear gradually or suddenly, and they may last less than an hour or for several days.
Headache
Headaches are generally classified by cause:
Primary headaches
A primary headache is caused by problems with or overactivity of pain-sensitive structures in your head. A primary headache isn't a symptom of an underlying disease. Chemical activity in your brain, the nerves or blood vessels of your head outside your skull, or muscles of your head and neck — or some combination of these factors — may play a role in primary headaches. Some people may carry genes that make them more likely to develop such headaches.
The most common primary headaches are:
- Cluster headache
- Migraine (with and without aura)
- Tension headache (medically known as tension-type headache)
- Trigeminal autonomic cephalalgia (TAC), including cluster headache and paroxysmal hemicrania
There are other headache patterns that are generally considered types of primary headache but are less common. These headaches have distinct features, such as an unusual duration or pain associated with a certain activity. Although these headaches are generally considered primary, each of them could be a symptom of an underlying disease. These headaches include:
- Chronic daily headaches
- Cough headaches
- Exercise headaches
- Sex headaches
Some primary headaches can be triggered by lifestyle factors, including:
Secondary headaches
A secondary headache is a symptom of a disease that can activate the pain-sensitive nerves of the head. Any number of conditions — varying greatly in severity — may cause secondary headaches. Sources of secondary headaches include:
- Acute sinusitis
- Arterial tears (carotid or vertebral dissections)
- Blood clot (venous thrombosis) within the brain — separate from stroke
- Brain aneurysm (a bulge in an artery in your brain)
- Brain AVM (an abnormal formation of brain blood vessels)
- (both cancerous and noncancerous)
- Carbon monoxide poisoning
- Chiari malformation (structural problem at the base of your skull)
- Concussion
- Dehydration
- Dental problems
- Ear infection (middle ear)
- Encephalitis (brain inflammation)
- Giant cell arteritis (inflammation of the lining of the arteries)
- Glaucoma
- Hangovers
- Influenza (flu)
- Intracranial hematoma (blood vessel ruptures in the brain)
- Medications to treat other disorders
- Meningitis (inflammation of the membranes and fluid surrounding your brain and spinal cord)
- Monosodium glutamate (MSG)
- Overuse of pain medication
- Panic attacks and panic disorder
- Post-concussion syndrome
- Pressure from tight-fitting headgear, such as a helmet or goggles
- Pseudotumor cerebri (increased pressure inside the skull)
- Toxoplasmosis
- Trigeminal neuralgia (disruption of the nerve connecting the face and brain)
Specific types of secondary headaches include:
- External compression headaches (a result of pressure-causing headgear)
- Ice cream headaches (commonly called brain freeze)
- Rebound headaches (caused by overuse of pain medication)
- Sinus headaches (caused by inflammation and congestion in sinus cavities)
- Spinal headaches (caused by low levels of cerebrospinal fluid, possibly the result of trauma, spinal tap or spinal anesthesia)
- Thunderclap headaches (a group of disorders that involves sudden, severe headaches)
Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.
Source: mayoclinic.org