Introduction
The pain from a headache does not start from inside the brain. (The brain itself can not feel pain.) Instead, headache pain begins in one or more of the following locations:
- The tissues covering the brain
- The structures at the base of the brain
- Muscles and blood vessels around the scalp, face, and neck
Headache is generally categorized as primary or secondary.
Primary Headache. A headache is considered primary when a disease or other medical condition does not cause it.
- Tension headache is the most common primary headache and accounts for 90% of all headaches. [For more information, see In-Depth Report # 11: Tension headaches.]
- Neurovascular headaches are the second most common primary headaches. This type includes migraines and cluster headaches. [For more information, see In-Depth Report # 99: Cluster headaches.] Such headaches are caused by an interaction between blood vessel and nerve abnormalities.
 | Click the icon to see a depiction of migraine cause. |
Secondary Headache. Secondary headaches are caused by other medical conditions, such as sinusitis, neck injuries or abnormalities, and stroke. About 2% of headaches are secondary headaches caused by abnormalities or infections in the nasal or sinus passages. [See Box: Causes of Secondary Headaches, in this report.]
It is not uncommon for someone to experience a combination of headache types.
 | Click the icon to see a comparison of headache symptoms. |
Migraine Headaches
Migraine is now recognized as a chronic illness, not simply as a headache. About 28 million people suffer from migraines annually. They are often classified by whether or not auras (seeing bright "spots" or "stars") accompany them:
- Common migraines are without auras. About 75% of migraines are the common type.
- Classic migraines are those with auras.
Previous Section
