Last Updated on October 13, 2025 by Analgesia team
What Is Giant Cell Arteritis (GCA)?
GCA is the medical abbreviation for Giant Cell Arteritis, a chronic autoimmune disease that causes inflammation in the walls of medium and large arteries.
It’s also called temporal arteritis, and it’s considered a medical emergency because of its potential to cause permanent vision loss and even stroke if left untreated
Giant Cell Arteritis is a type of vasculitis, which means inflammation of blood vessels. In GCA, the immune system mistakenly attacks the walls of medium and large arteries, especially in the head and neck.
The term “giant cell” comes from the presence of large immune cells seen under a microscope in biopsied artery tissue.
If left untreated, Giant Cell Arteritis can lead to permanent vision loss or a stroke. Prompt corticosteroid treatment can relieve symptoms and prevent vision loss in the other eye. Most people need to take steroids long-term to prevent symptoms from returning.
Why Is GCA a Medical Emergency?
Let’s make this clear:
Without fast treatment, GCA can lead to sudden and irreversible blindness — often starting in one eye and spreading to the other.
There’s also a risk of stroke, especially if the arteries supplying the brain become inflamed.
Symptoms of giant cell arteritis
Many people with GCA experience sudden symptoms that can be easily misdiagnosed if not recognised early. The inflammation affects medium and large arteries, especially those around the head and eyes, which explains the distinctive pattern of pain and visual problems.
The most common symptoms include:
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New or sudden headache — usually one-sided, affecting the temporal (side of the head) region. It may feel throbbing, sharp, or unlike any headache experienced before.
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Scalp tenderness — even light touch or brushing the hair can cause discomfort.
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Jaw claudication — pain, cramping, or tiredness in the jaw muscles while chewing or talking.
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Vision problems, such as blurred vision, double vision, or sudden vision loss in one eye, are medical emergencies that require urgent treatment to prevent blindness.
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Fatigue, fever, or unexplained weight loss — general symptoms caused by the body’s inflammatory response.
These symptoms can appear together or one at a time. Because GCA can damage blood flow to the eyes and brain, early recognition and immediate treatment are critical to prevent permanent complications.
Pro tip: If you’re over 50 and develop these symptoms, see a doctor immediately.
Who Does GCA Affect?
Giant cell arteritis (GCA) doesn’t strike randomly. It follows certain patterns — especially when it comes to age, gender, and genetic background.
Let’s break it down:
1. Adults over 50
GCA is almost never seen in younger people. The condition mainly affects adults over the age of 50, and the risk climbs sharply with each decade of life. Most diagnoses occur between 70 and 80 years old. Doctors believe that age-related changes in the immune system and blood vessels make older adults more vulnerable to this kind of inflammation.
2. Women
Women are about two to three times more likely than men to develop giant cell arteritis. Hormonal and genetic factors likely play a role, although researchers don’t yet know exactly why. Because of this higher risk, women over 50 with new headaches, scalp tenderness, or jaw pain should be evaluated quickly.
3. People of Northern European descent
GCA occurs far more often in people of Northern European ancestry, particularly those of Scandinavian heritage. It’s uncommon in people of African, Asian, or Southern European descent. This pattern suggests that genetic factors influence how the immune system responds to vascular inflammation.
4. Individuals with polymyalgia rheumatica (PMR)
There’s a strong link between giant cell arteritis and polymyalgia rheumatica (PMR) — another inflammatory condition that causes stiffness and aching in the shoulders and hips. About 10–20% of people with PMR eventually develop GCA, while around half of those with GCA also have PMR symptoms. Both diseases share similar immune pathways, which is why they often overlap.
How Is Giant Cell Arteritis Diagnosed?
Diagnosing giant cell arteritis (GCA) can be challenging because its symptoms often overlap with other conditions like migraines, sinus infections, or tension headaches. But when GCA is suspected, speed matters — delayed diagnosis can lead to irreversible vision loss or stroke.
Doctors rely on a mix of clinical signs, blood tests, and imaging or biopsy results to confirm the diagnosis. Here’s how it’s typically done:
1. Blood tests
Two key tests — erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) — help measure inflammation in the body. In GCA, these levels are usually very high, signalling an active inflammatory process. While raised ESR and CRP don’t confirm GCA alone, they strongly support the diagnosis when symptoms match.
2. Temporal artery biopsy
This is considered the gold-standard test. Under local anaesthetic, a small piece of the temporal artery (the vessel running along the side of the head) is removed and examined under a microscope.
If the artery shows inflammation with giant cells, the diagnosis is confirmed. Even so, a negative biopsy doesn’t completely rule out GCA, as inflammation can occur in segments — meaning the affected area might be missed.
3. Ultrasound of the temporal artery
Some doctors now use ultrasound as a non-invasive alternative or first step before biopsy. It can show the “halo sign” — a visible ring around the artery that indicates inflammation. Ultrasound helps speed up diagnosis, especially when a biopsy isn’t immediately available.
4. Imaging tests
In certain cases, MRI, CT angiography, or PET scans are used to detect inflammation in larger blood vessels, such as those in the chest or neck. This is known as large-vessel GCA and can cause symptoms beyond the head, like arm pain or chest discomfort.
In short:
A combination of symptoms, blood results, and imaging or biopsy findings confirms the diagnosis. Because GCA can cause serious complications in days, doctors often start treatment immediately — even before all test results are back.
Treatment Options for GCA
When giant cell arteritis (GCA) is suspected, treatment starts immediately — often before biopsy results are confirmed. The reason is simple: every hour counts. Delays in treatment can cause permanent vision loss or other serious complications.
The main goal is to stop artery inflammation quickly and protect the eyes and brain from reduced blood flow.
Here’s how treatment is managed:
1. High-dose corticosteroids
The first line of treatment is high-dose corticosteroids, usually prednisolone. These powerful anti-inflammatory drugs calm the immune system and relieve symptoms within days.
Patients with vision symptoms may receive intravenous methylprednisolone for a few days before switching to oral steroids.
Once symptoms improve, the steroid dose is gradually tapered over several months — sometimes even years — to find the lowest effective dose. The tapering process must be done slowly and under close supervision to prevent flare-ups.
2. Immunosuppressants
Because long-term steroid use can cause side effects like osteoporosis, weight gain, and diabetes, doctors often add steroid-sparing medications.
These include methotrexate or tocilizumab (an interleukin-6 inhibitor). Both help control inflammation and allow for lower steroid doses over time. Tocilizumab, in particular, has been shown to reduce relapses and may be given by injection or infusion.
3. Regular monitoring
Managing GCA is not a one-time event — it’s a process. Patients are monitored closely with regular blood tests (ESR and CRP) to track inflammation levels and frequent eye checks to protect vision.
Doctors also monitor blood pressure, blood sugar, and bone health because steroids can affect all three.
4. Lifestyle and supportive care
Calcium and vitamin D supplements are often prescribed to protect bone strength. A balanced diet, gentle exercise, and routine medical follow-up all help minimise side effects and maintain long-term health.
Bottom line:
With prompt and consistent treatment, most people with GCA recover well and avoid serious complications. The key is early recognition, immediate steroid therapy, and careful follow-up.
Possible Complications of Giant Cell Arteritis
If not properly treated, GCA can lead to:
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Permanent vision loss
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Stroke
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Aortic aneurysms — weakened areas in the aorta that can rupture
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Relapse — symptoms can return if treatment is stopped too early
FAQ About GCA
What does Giant Cell Arteritis mean in medical terms?
GCA stands for Giant Cell Arteritis, an autoimmune condition that inflames medium-to-large arteries, especially around the head and eyes.
Is GCA life-threatening?
Yes, if left untreated. It can cause blindness, stroke, or aortic aneurysms.
How long do you take steroids for GCA?
Treatment can last 1–2 years or longer, depending on how well the inflammation is controlled.
Can GCA be cured?
There’s no outright cure, but with proper treatment, most people can manage symptoms and prevent complications.
Key Takeaway
If you came here wondering what GCA medical abbreviation stands for, now you know it’s more than just a term — it’s a serious condition that demands fast action.
If you or someone you know is experiencing new headaches, vision changes, or jaw pain, especially after age 50, seek urgent medical help.