[2] The underlying mechanism involves inflammation of the small blood vessels that supply the walls of larger arteries.

[4][8] Diagnosis is suspected based on symptoms, blood tests, and medical imaging, and confirmed by biopsy of the temporal artery.

[1] Common symptoms of giant cell arteritis include: The inflammation may affect blood supply to the eye; blurred vision or sudden blindness may occur.

[17] The disorder may co-exist (in about half of cases) with polymyalgia rheumatica (PMR),[13] which is characterized by sudden onset of pain and stiffness in muscles (pelvis, shoulder) of the body and is seen in the elderly.

[19] These infiltrates erode the middle and inner layers of the arterial tunica media leading to conditions such as aneurysm and dissection.

[19] The gold standard for diagnosing temporal arteritis is biopsy, which involves removing a small part of the vessel under local anesthesia and examining it microscopically for giant cells infiltrating the tissue.

[24] Characterised as intimal hyperplasia and medial granulomatous inflammation with elastic lamina fragmentation with a CD4+ predominant T cell infiltrate, currently biopsy is only considered confirmatory for the clinical diagnosis, or one of the diagnostic criteria.

[25] Temporal artery thickening on imaging has been demonstrated to have highest positive likelihood ratios for GCA when compared with other non invasive diagnostic tests.

[26] Women and men approximately 45 years old and who suffer from several complaints (at least 5 of the 16 symptoms)[27] listed below could have giant cell arteritis.

Steroids do not prevent the diagnosis from later being confirmed by biopsy, although certain changes in the histology may be observed towards the end of the first week of treatment and are more difficult to identify after a couple of months.

[30] Short-term side effects of prednisone are uncommon but can include mood changes, avascular necrosis, and an increased risk of infection.

[31] Some of the side effects associated with long-term use include weight gain, diabetes mellitus, osteoporosis, avascular necrosis, glaucoma, cataracts, cardiovascular disease, and an increased risk of infection.

[38] Giant cell arteritis and its treatment impact on people's lives because of symptoms, adverse effects of GCs and disruption to normal life.

[39] People with GCA have previously ranked ‘losing sight in both eyes permanently’, ‘having intense or severe pain’ and ‘feeling weak, tired or exhausted’ as important quality of life domains.