Temporal arteritis is an inflammation of large arteries, most often the temporal arteries of the head. This inflammation narrows the arteries, reducing blood flow. In some instances, the artery may be blocked or close entirely.

Temporal arteritis, also known as giant cell arteritis, is characterized by dull, persistent pain in the head. This pain most often occurs in the temples, but may also affect the face, scalp, jaw and tongue. In many cases, the temporal arteries are tender and cord-like. Along with headaches and facial pain, patients may experience vision problems, from blurred or double vision to blindness. These signs and symptoms may be accompanied by low-grade fever and fatigue. 

Temporal arteritis occurs in about 200 of every 100,000 people over age 50, according to the National Institutes of Health (NIH).  It is most likely to occur in people in their 80s.  It is twice as common in women as in men and rarely affects people younger than age 50.

Temporal arteritis seems to be linked to polymyalgia rheumatica, a type of rheumatic disorder marked by muscle pain and stiffness.  The NIH estimates that about half of all temporal arteritis patients also have polymyalgia rheumatica. About 15 percent of people with polymyalgia rheumatica also have temporal arteritis.

The cause of temporal arteritis is not known. Diagnosis relies on medical history, a physical examination, blood tests and an arterial biopsy to determine if cells lining the arteries are enlarged. Other tests, such as ultrasound, may also be used in diagnosis.