Answer:
Dear
Blaq,
Tension
headaches are the most common type of primary headache. Up to 90%
of adults have had or will have tension headaches.
Researchers
think that tension-type headaches occur due to an interaction of different
factors that involve pain sensitivity and perception, as well as the
role of brain chemicals (neurotransmitters).
Genetic
factors are likely be involved in chronic tension-type headache, whereas
environmental factors (physical and psychological stress) may play
a role in the physiologic processes involved with episodic tension-type
headache.