Up until recently, physicians and scientists thought that tightness in muscles and blood vessels cause headache pain.

The Traditional Culprits

The Trigeminal Nerve

While tight muscles and blood vessels do play a big role in head pain, scientists are finding that there are more complex causes for headaches. Many experts now think that migraine and tension headaches may come from the same place in the brain—the trigeminal nerve.

The trigeminal nerve starts deep in the brain stem and fans out to almost all parts of the face. Feelings of pain that travel along the trigeminal nerve from your face to your brain often cause headaches.

Serotonin

Serotonin, a natural chemical in the body, also plays a role. Serotonin stops the feeling of pain from moving along the trigeminal nerve. When serotonin levels are low, the pain moves more easily along the nerve. There are lots of reasons for low levels of serotonin. It may be something that runs in your family or be related to depression or high levels of stress.

Do different headaches have different causes?

Scientists now think that most headaches occur on a continuum that covers a range of pain levels. Tension headache is on one end and migraine on the other. This means that people who usually get tension headaches can sometimes experience migraine-like symptoms, while people who usually suffer from migraine can sometimes experience tension headache symptoms, depending on the number and type of triggers.