It is estimated that 75 to 90 percent of all chronic or frequent headaches are tension headaches. Tension headaches are the most common type of primary headache, and while they share some characteristics with the migraine headaches and other types, they also display certain distinct differences that set them apart.
Some experts believe that tension headaches and migraines represent two ends of a common spectrum, and that migraines, which are severe but irregular in occurrence, sometimes progress or transform to the less severe, but more frequent, tension-variety headache.
Physical Findings: Tension Headaches
Physical examination often reveals muscular tenderness in areas of the neck, the base of the skull, shoulders, upper arms, jaw, and face. Tension headache may cause a person to clench their jaw and teeth. The scalp and forehead may also be painful when palpated. Neurological examination is usually normal.