Headache is the commonest neurological disorder in the community with variable intensity, ranging from a trivial nuisance to a severe, disabling, acute or chronic disorder, and may impose a substantial burden on sufferers and on society. It is one of the commonest reasons for visiting the neurology clinics worldwide, exerting significant burden on its sufferers and impairing daily function especially when accompanied by other symptoms, hence adversely affecting quality of life.

Headaches can occur as a result of many conditions whether serious or not. There are a number of different classification systems for headaches. 

Headaches are broadly classified as "primary" or "secondary". Primary headaches are benign, recurrent headaches not caused by underlying disease or structural problems. While primary headaches may cause significant daily pain and disability, they are not dangerous. Secondary headaches are caused by an underlying disease, like an infection, head injury, vascular disorders, brain bleed or tumors. Secondary headaches can be harmless or dangerous. 

90% of all headaches are primary headaches. Primary headaches usually first start when people are between 20 and 40 years old . The most common types of primary headaches are migraines and tension-type headaches. Other very rare types of primary headaches include: 

  • migrene: a neurological disorder that manifests as recurrent attacks of headache that are typically throbbing and unilateral and often severe, with associated features such as hypersensitivity to multiple stimuli, including visual, auditory, and sensory stimuli during migraine attacks.
  • cluster headaches: cluster headaches are a neurological disorder characterized by recurrent, severe headaches on one side of the head, typically around the eye often accompanied by autonomic symptoms such as eye watering, nasal congestion and swelling around the eye.
  • trigeminal neuralgia: shooting face pain.
  • hemicrania continua: continuous unilateral (one sided) pain with episodes of severe pain. 
  • primary cough headache: a headache triggered by rapid increases in intra-abdominal pressure, caused by coughing, sneezing or straining. 
  • primary sex headache: dull, bilateral headache that starts during sexual activity and becomes much worse during orgasm. It is important to realize that headaches that begin during orgasm may be due to a subarachnoid hemorrhagie (bleeding into the area between the arachnoid membrane and the pia mater surrounding the brain), so serious causes must be ruled out first. 
  • hypnic headache: moderate-severe headache that starts a few hours after falling asleep and lasts 15–30 minutes. The headache may recur several times during night. 

Headaches may be caused by problems elsewhere in the head or neck. Some of these are not harmful, such as cervicogenic headache (pain arising from the neck muscles). Medication overuse headache may occur in those using excessive painkillers for headaches, paradoxically causing worsening headaches. 

More serious causes of secondary headaches include: 

  • meningitis: inflammation of the meninges which presents with fever and meningismus, or stiff neck
  • bleeding inside the brain (intracranial hemorrhage)
  • brain tumor: dull headache, worse with exertion and change in position, accompanied by nausea and vomiting. Often, the person will have nausea and vomiting for weeks before the headache starts.
  • temporal arteritis: inflammatory disease of arteries common in the elderly (average age 70) with fever, headache, weight loss, jaw claudication, tender vessels by the temples, polymyalgia rheumatica
  • acute closed angle glaucoma (increased pressure in the eyeball): headache that starts with eye pain, blurry vision, associated with nausea and vomiting. On physical exam, the person will have a red eye and a fixed, mid dilated pupil.
  • post-ictal headaches: Headaches that happen after a convulsion or other type of seizure, as part of the period after the seizure (the post-ictal state)

Headache is a symptom of several diseases of reproduction system such as orchitis, mumps and amenorrhea. 

Orchitis and mumps 

Orchitis and mumps are infectious diseases. In response to every infection the body creates molecular inflammatory mediators which can influnce blood vessel spasm or stimulate nociceptors (a type of sensory receptor at the end of a neuron that responds to damaging or potentially damaging stimuli by sending signals of pain to the spinal cord and brain). 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.

Amenorrhea

Amenorrhea (the absence of menstrual bleeding) can be caused by tumor in hypothalamus or pitutary gland due to disruption of hormonal activity. Very often the first signs of tumor are three main symptoms- amenorrhea, headache (caused by expansive proccess in head which leads to high pressure in head) and visual fields defect.

Find more about related issues

Sources

Inflammation ―sourced from Wikipedia licensed under CC BY- SA 3.0
Cluster headache ―sourced from Wikipedia licensed under CC BY- SA 3.0
Headache ―sourced from Wikipedia licensed under CC BY- SA 3.0
Headache associated with cough: a review ―by Cordenier et al. licensed under CC BY 2.0
Migraines and Headaches - types and causes ―sourced from Soothe licensed under CC BY- SA 2.5
Creative Commons License
Except where otherwise noted, content on this site is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License, involving multiple copyrights under different terms listed in the Sources section.