Headaches are one of the most common medical complaints; most people experience them at some point in their life. They can affect anyone regardless of age, race, and gender. A headache can occur in any part of the head, on both sides of the head, or in just one location.
Headaches can radiate across the head from a central point or have a vise-like quality. They can be sharp, throbbing or dull, appear gradually or suddenly. They can last from less than an hour up to several days.
There are different ways to define headaches. The International Headache Society (IHS) categorizes headaches as primary, when they are not caused by another condition, or secondary, when there is a further underlying cause.
Primary headaches are stand-alone illnesses caused directly by the overactivity of, or problems with, structures in the head that are pain-sensitive.
This includes the blood vessels, muscles, and nerves of the head and neck. They may also result from changes in chemical activity in the brain.
Common primary headaches include migraines, cluster headaches, and tension headaches.
Secondary headaches are symptoms that happen when another condition stimulates the pain-sensitive nerves of the head. In other words, the headache symptoms can be attributed to another cause.
A wide range of different factors can cause secondary headaches. Common secondary headaches include
- Teeth-grinding at night
- Overuse of pain medication, known as rebound headaches
- Neck problems especially degenerative disc disease and arthritis in neck.