While the exact cause of giant cell arteritis is unknown, the condition occurs when arteries become inflamed and swell, which, in some cases decreases the flow of blood, as noted by Mayo Clinic. Giant cell arteritis most often occurs in the temporal arteries, which are positioned just in front of the ears. Because of this, it is sometimes called cranial arteritis or temporal arteritis.
Giant cell arteritis is defined as an inflammation of the lining of the arteries, the blood vessels that carry oxygen to the various parts of the body. The inflammation and swelling may occur through the entire artery, or may just affect certain sections, with normal vessel between them. Symptoms of this condition include headaches or other head pain with tenderness in the temple, loss of vision or double vision, sudden vision loss in one eye, tenderness on the scalp, jaw pain when opening the mouth wide or chewing, unexplained weight loss and fever. The first signs of giant cell arteritis can vary, but some people report flu-like symptoms such as muscle aches and fatigue.
The condition is diagnosed by several means, including physical exams, blood tests, biopsies, magnetic resonance angiography, doppler ultrasound and positron emission tomography. Giant cell arteritis is treated with prednisone or other corticosteroid drugs given in large doses. Doctors may start this treatment immediately, even before confirming the diagnosis, in order to prevent vision loss.