Iliac disease refers to conditions that block or damage the iliac arteries or veins, the large blood vessels in your pelvis that supply blood to your legs and lower body. The most common form is atherosclerotic narrowing of the iliac arteries, where fatty plaques build up inside the vessel walls and gradually restrict blood flow. Less commonly, the term covers iliac vein compression and iliac artery aneurysms. All of these conditions can cause significant pain and, if untreated, serious complications.
Where the Iliac Vessels Are and Why They Matter
Your aorta, the body’s largest artery, splits into two branches at about the level of your belly button. These are the common iliac arteries, one for each side. Each common iliac artery then divides again into an internal branch (which feeds the pelvic organs) and an external branch (which continues down into the leg and becomes the main artery of the thigh). The iliac veins run alongside these arteries, carrying blood back up toward the heart.
Because virtually all blood flowing to and from your legs passes through these vessels, any obstruction here has widespread effects. Blockages in the iliac arteries reduce blood flow not just to the legs but also to the buttocks, hips, and pelvic organs.
Iliac Artery Disease: The Most Common Form
The process starts with damage to the inner lining of the artery wall. Risk factors like smoking, high blood pressure, high cholesterol, and diabetes injure this lining, triggering inflammation. White blood cells and fats begin accumulating in the vessel wall, and over time these deposits harden into calcified plaques that narrow the artery’s opening. This is the same process (atherosclerosis) that causes heart attacks and strokes, just in a different location.
Blockages most often develop in the common iliac arteries or external iliac arteries, though they can appear in any combination of the iliac branches and the lower portion of the aorta. When disease involves both the aorta and the iliac arteries, it’s called aortoiliac occlusive disease.
Symptoms of Iliac Artery Blockages
The hallmark symptom is pain in the buttocks, hips, or thighs that comes on with walking and goes away with rest. This is called claudication, and it happens because your leg muscles need more blood during exercise than the narrowed arteries can deliver. The pain typically starts after walking a predictable distance and forces you to stop. Unlike leg pain from a pinched nerve in the spine, which often worsens when standing upright and improves when leaning forward, vascular claudication reliably eases within a few minutes of simply standing still.
Because the iliac arteries also supply the pelvic organs, blockages can cause erectile dysfunction in men. Low back and groin pain while walking short distances are also common. In severe cases where blood flow drops critically low, you may experience pain even at rest, particularly in the feet, or develop wounds on the legs that won’t heal.
How Iliac Artery Disease Is Diagnosed
The first screening tool is usually an ankle-brachial index (ABI) test, which compares blood pressure at your ankle to blood pressure in your arm. A significant drop at the ankle suggests blocked arteries somewhere between the heart and the foot. Imaging with CT angiography, MR angiography, or ultrasound then pinpoints where the blockages are and how severe they’ve become. In some cases, catheter-based angiography (where dye is injected directly into the arteries) provides the most detailed view and can double as a treatment opportunity.
Risk Factors
The four major drivers are smoking, diabetes, high blood pressure, and high cholesterol. Each of these damages the artery lining through slightly different mechanisms, but they all promote inflammation, reduce the artery’s ability to relax and dilate, and encourage plaque formation. Smoking is the single strongest risk factor for peripheral artery disease overall. Having multiple risk factors compounds the damage significantly.
Treatment: Medications and Lifestyle
For milder disease, the first approach combines medications with lifestyle changes. The 2024 ACC/AHA guidelines recommend high-intensity statin therapy to lower LDL cholesterol to below 70 mg/dL, aiming for at least a 50% reduction. Antiplatelet therapy (typically low-dose aspirin) reduces the risk of heart attack and stroke, since iliac artery disease signals atherosclerosis throughout the body. For appropriate patients who aren’t at high bleeding risk, adding a low-dose blood thinner to aspirin further lowers the chance of both cardiovascular events and limb complications.
Supervised exercise programs are a cornerstone of treatment. Structured walking programs, where you walk until symptoms appear, rest, then resume, can substantially improve the distance you’re able to cover before pain sets in.
Treatment: Stenting and Surgery
When symptoms persist despite medications and exercise, or when blood flow is critically compromised, procedures to physically reopen the artery become necessary. The first-line approach today is endovascular, meaning it’s done through a catheter inserted into the artery rather than through open surgery. A balloon is inflated at the blockage site, and a metal stent is placed to hold the artery open. Procedural success rates for iliac artery stenting exceed 95%, and four-year patency rates (meaning the artery stays open) range from 82% to 94% depending on the study and technique.
Open surgical bypass, where a synthetic graft reroutes blood around the blockage, is reserved for extensive disease that isn’t suitable for stenting. A classification system called TASC helps clinicians decide: simpler, shorter blockages are treated with stents, while long, complex occlusions involving multiple vessels or heavy calcification are better candidates for bypass surgery. Bypass offers excellent long-term durability but involves a larger operation with a longer recovery.
Indications for any procedure include severe claudication that limits daily life despite medical therapy, rest pain, non-healing leg wounds, gangrene, and erectile dysfunction caused by pelvic blood flow restriction.
Iliac Artery Aneurysms
Less commonly, the iliac arteries can weaken and balloon outward rather than narrowing. These aneurysms often produce no symptoms until they grow large enough to press on nearby structures or rupture. Current evidence suggests that iliac artery aneurysms reaching 30 mm (about 1.2 inches) in diameter warrant close monitoring or surgical repair, because the rate of expansion accelerates at that size, increasing rupture risk. Repair can be done with an endovascular stent graft or open surgery depending on the aneurysm’s anatomy.
May-Thurner Syndrome: Iliac Vein Disease
Iliac disease doesn’t always involve the arteries. In May-Thurner syndrome, the right common iliac artery compresses the left common iliac vein against the spine. Over time, the chronic pulsing pressure causes scar tissue and fibrous “spurs” to form inside the vein, partially or completely blocking it. Anatomical studies have found these spur formations in roughly 22% of cadavers, suggesting the compression is common, though only a fraction of people develop symptoms.
When symptoms do appear, they typically involve swelling, pain, and heaviness in the left leg. The major risk is deep vein thrombosis (DVT), and May-Thurner syndrome is one reason DVT occurs more frequently in the left leg than the right. Diagnosis can be tricky because there are no standardized criteria, but imaging that shows more than 50% narrowing of the vein’s diameter, along with the presence of internal spurs or rerouted blood flow through collateral veins, supports the diagnosis. Treatment usually involves placing a stent inside the compressed vein to hold it open, sometimes after first dissolving or removing a blood clot.
How Iliac Disease Differs From Other Leg Pain
Iliac artery disease is often confused with spinal stenosis, hip arthritis, or sciatica because all of these can cause pain in the buttocks, hips, and legs with activity. A few distinguishing features help sort them out. Iliac artery claudication produces a cramping or aching sensation that starts reliably with a certain amount of walking and resolves quickly (within two to five minutes) once you stop, regardless of your posture. Spinal stenosis pain tends to worsen with standing straight and improve with sitting or bending forward. Hip arthritis pain is typically worst with the first steps after rest and localizes to the groin or outer hip. If you notice that your legs feel heavy or crampy only during exertion and fine at rest, reduced blood flow is a likely explanation worth investigating.