Giant cell arteritis
An inflammation of medium and large arteries, especially those around the temples and head, occurring in older adults. It causes a new headache, scalp tenderness and jaw pain, and can threaten vision — so suspected cases need urgent assessment and treatment to protect eyesight.
What it is
Giant cell arteritis (also called temporal arteritis) is a form of vasculitis — inflammation of blood vessel walls — that affects medium and large arteries, particularly the branches of the arteries supplying the head, scalp and eyes. It occurs almost exclusively in people over 50 and becomes more common with age. The inflammation thickens the artery walls and narrows them, reducing blood flow to the tissues they supply. Typical features are a new headache (often over the temples), tenderness of the scalp (for example when combing hair), pain in the jaw when chewing (jaw claudication), and tenderness or reduced pulsation of the temporal artery. The most feared complication is sudden, often painless, loss of vision in one eye, which can become permanent and can affect the other eye if untreated — this is what makes the condition a medical emergency. It is closely linked to polymyalgia rheumatica, and many people have overlapping shoulder and hip girdle pain and stiffness, fever, fatigue and weight loss. Blood tests characteristically show markedly raised inflammatory markers — ESR and CRP — often with a raised platelet count. The diagnosis is confirmed by a temporal artery biopsy or vascular imaging, but because vision is at risk, treatment with high-dose steroids is usually started immediately on strong suspicion, before confirmation. Prompt treatment is highly effective at preventing blindness.
Key lab markers
- ESR — characteristically very high; a key supporting test, though occasionally normal.
- CRP — raised, and a sensitive marker of the inflammation.
- Platelets — often raised (thrombocytosis), adding to the picture.
- Full blood count — may show anemia of chronic inflammation.
- Temporal artery biopsy or vascular imaging — confirms the diagnosis, but treatment is not delayed for it when vision is at risk.
Symptoms
- New headache, often over the temples
- Scalp tenderness (e.g. painful when combing hair)
- Jaw pain or fatigue when chewing (jaw claudication)
- Sudden visual loss or double vision — a medical emergency
- Tender or thickened temporal artery
- Shoulder and hip girdle pain and stiffness (overlap with polymyalgia rheumatica)
- Fever, fatigue, weight loss
Related lab panels
When to discuss with a doctor
Giant cell arteritis is a medical emergency because it can cause sudden, permanent loss of vision. Seek urgent medical care if you are over 50 and develop a new persistent headache, tenderness of the scalp, jaw pain when chewing, or especially any change in vision — and do not wait if vision is affected. High-dose steroid treatment started promptly is very effective at protecting sight, so doctors usually begin it immediately when the suspicion is strong, even before a biopsy or scan confirms it. Markedly raised inflammatory markers support the diagnosis. Mediora.AI can flag very high ESR and CRP, often with raised platelets, a pattern that fits giant cell arteritis in an older adult, but this is a time-critical condition — new headache or visual symptoms in someone over 50 need urgent assessment by a doctor, not watchful waiting.