Giant cell arteritis is a serious inflammatory condition affecting blood vessels in the head, neck, and arms, most commonly seen in people over age 50. Without rapid treatment, it can lead to permanent vision loss or stroke.
Epidemiology
Giant cell arteritis, also called temporal arteritis, is one of the most common forms of vasculitis (inflammation of blood vessels) in adults, but it remains relatively uncommon overall. In the United States, approximately 19 to 23 out of every 100,000 people develop this condition each year. Studies from New Zealand have shown similar rates, with about 12 cases per 100,000 people over age 50 annually.[2][4]
The disease is strongly linked to age, appearing almost exclusively in people older than 50 years. The average age at which giant cell arteritis develops is around 70 years, with the highest occurrence between ages 70 and 80. It is extremely rare in younger individuals, making age one of the most important risk factors for this condition.[2][4]
Women experience giant cell arteritis more frequently than men, with females being two to three times more likely to develop the disease. However, an important finding shows that when men do develop giant cell arteritis, they face a higher risk of experiencing the most serious complication: blindness. This suggests that the disease may behave differently or more aggressively in males.[2][5][7]
Race and ethnicity also play significant roles in who develops giant cell arteritis. The condition predominantly affects people of Northern European descent, particularly those of Scandinavian heritage. It is considerably less common in Mediterranean populations and rarely occurs in people of African or Asian descent. This geographic and ethnic pattern suggests that genetic factors may contribute to susceptibility to the disease.[2][5]
Causes
The exact cause of giant cell arteritis remains unknown to medical researchers. However, many experts believe it is an autoimmune or autoinflammatory disease, meaning the body’s own immune system mistakenly attacks healthy blood vessels. In this condition, the immune system targets the walls of large and medium-sized arteries, particularly those in the head, neck, and arms, causing them to become inflamed and narrowed.[2][5]
Genetic factors appear to play a role in the development of giant cell arteritis. The disease has been linked to a specific genetic marker called the HLA-DRB1*04 allele, which suggests that some people may be born with a predisposition to developing the condition. This genetic connection helps explain why certain ethnic groups have higher rates of the disease than others.[4]
Because giant cell arteritis occurs almost exclusively in older adults, researchers believe the aging process itself may contribute to the disease’s development. As the body ages, changes in the immune system and blood vessels may create conditions that allow inflammation to occur more easily. Environmental factors, such as infections, are also thought to play a role, potentially triggering the immune system in ways that lead to the disease in genetically susceptible individuals.[2][5]
Risk Factors
Age stands as the single most significant risk factor for giant cell arteritis. The disease almost never occurs in people under 50 years old, and the risk increases substantially as people move through their 60s, 70s, and 80s. If you are over 50 and experience new or unusual headaches, you should be aware that giant cell arteritis is a possibility that needs to be ruled out.[2][4]
Being female increases the likelihood of developing giant cell arteritis. Women develop the condition two to three times more often than men, though the reasons for this gender difference are not fully understood. Despite the higher occurrence in women, men who develop the disease face greater risks of serious complications, particularly vision loss.[2][5]
Racial and ethnic background significantly influence risk. People of Northern European descent, especially those with Scandinavian ancestry, have the highest rates of giant cell arteritis. White individuals are far more likely to develop the condition compared to people of African or Asian descent. This racial pattern points to genetic factors that may make certain populations more vulnerable.[2][5]
Having polymyalgia rheumatica, an inflammatory condition that causes pain and stiffness in the shoulders and hips, increases the risk of developing giant cell arteritis. About 5 to 15 percent of people with polymyalgia rheumatica will eventually develop giant cell arteritis. Conversely, approximately 40 to 60 percent of people with giant cell arteritis also have symptoms of polymyalgia rheumatica. The two conditions are closely related, and anyone diagnosed with polymyalgia rheumatica should be monitored for signs of giant cell arteritis.[2][3]
Symptoms
The most common symptom of giant cell arteritis is a new, persistent headache, which occurs in 40 to 90 percent of patients. This headache is often severe and typically affects both temples, though it can occur anywhere on the head. The pain may progressively worsen, come and go, or temporarily subside, but it is usually continuous and throbbing in nature. Many people describe the headache as different from any they have experienced before.[1][4]
Scalp tenderness is another characteristic symptom of giant cell arteritis. Many people notice pain or discomfort when brushing or washing their hair, or when lying on one side of their head while sleeping. The tenderness is often most noticeable over the temples, where the temporal arteries run just beneath the skin. In some cases, the temporal arteries may appear swollen, cord-like, or thickened, and they may have a reduced pulse when touched.[1][4]
Jaw pain when chewing or talking, called jaw claudication, is a particularly concerning symptom that strongly suggests giant cell arteritis. This pain typically worsens after a few minutes of chewing and may extend to the ear, tongue, throat, or neck. Some people experience fatigue in their jaw muscles when eating or swallowing. Jaw claudication is considered a red flag symptom that should prompt immediate medical evaluation.[1][4]
Vision problems are among the most serious symptoms of giant cell arteritis. These can include double vision, blurry vision, or temporary vision loss in one eye that comes and goes. About one-third of patients who eventually lose vision permanently experience brief episodes of temporary vision loss in one eye 7 to 10 days beforehand. This temporary loss, which may feel like a curtain being pulled over the eye, is a critical warning sign. Permanent vision loss can occur suddenly and is typically severe and irreversible, even with treatment. Vision loss affects one or both eyes in 20 to 50 percent of untreated patients.[1][4]
Many people with giant cell arteritis experience general symptoms that resemble the flu. These include fatigue, fever, loss of appetite, unintentional weight loss, and an overall feeling of being unwell or having decreased energy. Some people may experience night sweats or depression. These nonspecific symptoms can make the condition difficult to recognize early on.[1][4]
When giant cell arteritis occurs alongside polymyalgia rheumatica, patients experience additional symptoms of pain and stiffness in the muscles around the shoulders, neck, hips, upper thighs, lower back, and buttocks. This muscle discomfort is usually worse in the morning and can significantly affect mobility and quality of life.[1][2]
Less common but serious symptoms can include numbness, tingling, hearing loss, dizziness, problems with coordination and balance, persistent sore throat, difficulty swallowing, tongue pain, and occasional chest pain. In severe cases, giant cell arteritis can lead to stroke, transient ischemic attacks (mini-strokes), heart attack, or kidney damage.[1][4]
Prevention
Unfortunately, there are no known strategies to prevent giant cell arteritis from developing, as the exact cause of the disease remains unclear. The condition is believed to result from a combination of genetic predisposition, immune system changes associated with aging, and possibly environmental triggers that cannot be avoided or modified.[2][5]
However, preventing the serious complications of giant cell arteritis is entirely possible through early recognition and prompt treatment. The most important preventive measure is awareness of the warning signs, especially for people over 50 years old. Being alert to symptoms such as new persistent headaches, jaw pain with chewing, vision changes, or scalp tenderness can lead to earlier diagnosis and treatment.[1][6]
People diagnosed with polymyalgia rheumatica need regular monitoring for signs of giant cell arteritis, since the two conditions are closely linked. Reporting any new symptoms such as headaches, vision changes, or jaw pain to a healthcare provider is vital, even if polymyalgia rheumatica symptoms are well controlled or inactive.[3]
Once giant cell arteritis is diagnosed, proper nutrition, physical activity, and rest are important for overall health during treatment. Following the prescribed medication regimen carefully is essential to prevent complications. Some studies suggest that taking low-dose aspirin (81 mg daily) may help prevent vision loss and stroke in people with giant cell arteritis, though this should only be done under medical supervision and if there are no contraindications.[5][16]
Regular follow-up appointments with healthcare providers allow for monitoring of disease activity and adjustment of treatment as needed. Since corticosteroid therapy, the main treatment for giant cell arteritis, can cause bone loss, doctors may recommend bone density testing and supplements such as vitamin D, calcium, or medications called bisphosphonates to prevent osteoporosis and bone fractures.[3][13]
Pathophysiology
Giant cell arteritis causes inflammation in the walls of medium and large arteries throughout the body. The condition particularly affects the arteries in the head, neck, and arms, with the temporal arteries near the temples being most commonly involved. However, autopsy and imaging studies have shown that the disease can affect much larger vessels, including the aorta and its major branches, in up to 80 to 83 percent of cases.[4]
The inflammatory process in giant cell arteritis involves the immune system attacking the layers of the artery walls. When examined under a microscope, affected arteries show large or “giant” cells, which is how the disease gets its name. The inflammation has a granulomatous nature, meaning it forms specific patterns of immune cells. This process leads to the loss of vascular smooth muscle cells and elastic fibers in the artery walls, which can potentially result in aneurysm formation and vascular remodeling.[4][6]
As inflammation progresses, it causes the inner lining of the arteries to thicken, a process called intimal hyperplasia. This thickening narrows the space through which blood flows, restricting blood supply to the tissues and organs that depend on those arteries. When blood flow is reduced or blocked, the affected tissues become starved of oxygen, leading to ischemic (oxygen-deprived) complications.[6]
When the temporal arteries become inflamed and narrowed, blood supply to the scalp, jaw muscles, and the optic nerve in the eye is reduced. This explains many of the characteristic symptoms of giant cell arteritis. The reduced blood flow to the scalp causes headaches and tenderness. When jaw muscles don’t receive enough blood during the increased demands of chewing, it causes jaw claudication. Most seriously, when the optic nerve or retina loses its blood supply, it leads to vision loss.[2][4]
Vision loss in giant cell arteritis typically results from ischemic optic neuropathy, which means the optic nerve dies from lack of blood supply. This damage is usually severe and almost always irreversible, even with treatment. The inflammation can also affect blood vessels supplying the retina, causing additional damage to vision. If not treated promptly, the inflammation can spread to affect the other eye, typically within 7 to 10 days in 70 percent of cases.[4]
When giant cell arteritis affects larger vessels like the aorta and its branches, it can cause inflammation of the aorta called aortitis. This can lead to serious health problems including large-vessel stenosis (narrowing), aneurysms (weakening and bulging of artery walls), stroke, heart attack, and in severe cases, kidney damage. The inflammatory process can also cause symptoms in the limbs, such as limb claudication (pain with use), asymmetric blood pressures between arms, and abnormal pulses.[2][6]
Blood tests in people with giant cell arteritis typically show elevated markers of inflammation. The erythrocyte sedimentation rate (sed rate), which measures how quickly red blood cells settle in a test tube, is almost always elevated in giant cell arteritis. Red blood cells settle more quickly when inflammation is present in the body. Another marker, C-reactive protein (CRP), which the liver produces during inflammation, is also usually elevated. Most patients also have mild anemia, or low red blood cell count. However, a small percentage of patients with giant cell arteritis may have normal blood test results, so normal tests do not completely rule out the disease.[3][7][10]
