Giant cell arteritis—also known as temporal arteritis—is an inflammation of the blood vessels in the temple area of the scalp. This condition can cause permanent blindness if not treated promptly.

Giant cell arteritis causes a headache that begins as a dull, throbbing ache on one side of the head around the eye or near the temple. The headache is usually worse when the person is lying flat and improves when the person is sitting upright. A person can also have pain in the jaw when chewing.

Giant cell arteritis mostly affects people over age 60.