The term vascular headache refers to a group of headache conditions in which blood vessel dilation or swelling is the major component in the production of pain. The blood vessels in the tissues surrounding the head swell, become distended and inflamed, so that the normal pulsation of the vessels causes a throbbing type of pain.
Vascular headaches are usually throbbing in character, and physical exertion increases the pain. Included under the classification of vascular headaches are migraine headaches, cluster headaches, and toxic headaches. All involve dilation, or swelling of the blood vessels in the head and scalp.