[4][5] The 2016 Global Burden of Disease study revealed that TTHs affect about 1.89 billion people and are more common in women than men (30.8% to 21.4% respectively).

Despite its benign character, tension-type headache, especially in its chronic form, can impart significant disability on patients as well as burden on society at large.

[citation needed] Various precipitating factors may cause tension-type headaches in susceptible individuals:[8] Although the musculature of the head and neck and psychological factors such as stress may play a role in the overall pathophysiology of TTH, neither is currently believed to be the sole cause of the development of TTH.

[8] Pericranial tenderness is also not likely a peripheral causal factor for TTH, but may instead act to trigger a chronic pain cycle.

Evidence also suggests that dysfunction in supraspinal descending inhibitory pain pathways may contribute to the pathogenesis of central sensitization in CTTH.

[8] Briefly, the enzyme nitric oxide synthase (NOS) forms NO which ultimately results in vasodilatation and activation of central nervous system pain pathways.

[8] Serotonin may also be of significant importance and involved in malfunctioning pain filter located in the brain stem.

However, the analgesic effect of nortriptyline, as well as amitriptyline in chronic tension-type headache, is not solely due to serotonin reuptake inhibition, and likely other mechanisms are involved.

[8] With TTH, the physical exam is expected to be normal with perhaps the exception of either pericranial tenderness upon palpation of the cranial muscles, or presence of either photophobia or phonophobia.

This classification system separates tension-type headache (TTH) into two main groups: episodic (ETTH) and chronic (CTTH).

Screening for giant cell arteritis involves the blood tests of erythrocyte sedimentation rate (ESR) and c-reactive protein.

[22] Over-the-counter drugs, like paracetamol, or NSAIDs (ibuprofen, aspirin, naproxen, ketoprofen), can be effective but tend to only be helpful as a treatment for a few times in a week at most.

[24] Classes of medications involved in treatment of CTTH include tricyclic antidepressants (TCAs), SSRIs, benzodiazepine (Clonazepam in small evening dose), and muscle relaxants.

The most commonly utilized TCA is amitriptyline due to the postulated role in decreasing central sensitization and analgesic relief.

A 2016 systematic review suggests better evidence among those with frequent tension headaches, but concludes that further trials comparing acupuncture with other treatment options are needed.

[25] People with tension-type headache often use spinal manipulation, soft tissue therapy, and myofascial trigger point treatment.

A 2006 systematic review found no rigorous evidence supporting manual therapies for tension headache.

[28] A 2012 systematic review of manual therapy found that hands-on work may reduce both the frequency and the intensity of chronic tension-type headaches.

[32] Despite its benign character, tension-type headache, especially in its chronic form, can impart significant disability on patients as well as burden on society at large.