Tension Headache (TH), the most common type of headache, is associated with a dull or sharp, persistent, mild to severe pain that's often described as feeling like a tight band around your head. A global study found around 38% of adults suffer tension headaches, compared with 10% who suffer migraines. Onset is often in the teenage years, peaks in the forties then declines in later years.

TH can be intermittent, with episodes lasting anywhere between half an hour to a week, or chronic, where the headaches are experienced more than fifteen days a month for three months or more. Without adequate treatment, about half of patients have a headache every day for ten or more years.

Tension headaches can be difficult to distinguish from migraines because there are many overlapping features. Both can be associated with dizziness, sensitivity to light and noise, nausea, difficulty concentrating, short term memory loss, "foggy" thinking, depression and anxiety. Both have tenderness in the scalp tissues and head muscles, but in TH the tenderness is significantly greater than migraineurs. Plus, around 10% of tension headache patients also have migraines.

Head tenderness associated with nodules and lumps (fibrotic change) formed in the scalp tissue and head muscles is believed to be a significant source of pain and nerve activity triggering symptoms in many migraine and TH sufferers. Studies have found that the greater the tenderness in head muscles the greater the frequency of TH. Excessive clenching or bracing of the jaw muscles is a major cause of TH. Such bracing can be driven by physical, emotional, and mental factors, such as posture, habit, frustration, anger, determination and prolonged concentration.