Popliteal Artery Aneurysm: Symptoms, Causes, Treatment & Complete Guide
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 17, 2026
Quick Answer
A popliteal artery aneurysm is an irregular bulge in the wall of the artery behind the knee. It may cause no symptoms, though leg pain with walking is often the first sign. The main danger is blood clots that cut off blood flow and can cause limb loss. Surgery is usually advised if symptomatic or about 2 centimeters or larger.
What the research says
Open repair had better one-year patency but more wound complications. A systematic review and meta-analysis of 32 studies found that, compared with endovascular repair, open surgery was associated with higher primary patency at 1 year (odds ratio 2.10; 95% CI 1.41–3.12) and fewer reinterventions (OR 0.28; 95% CI 0.17–0.45), but a longer hospital stay and more wound complications (OR 5.18; 95% CI 2.19–12.26); there was no significant difference in 3-year primary patency, mortality, or amputation, and the certainty of the evidence was generally low. (Beuschel et al., J Vasc Surg, 2022) [3]
A popliteal aneurysm is a marker for aneurysms elsewhere. In a systematic review of 32 studies including 16,353 patients, about one in six patients with a primary aneurysm (weighted co-prevalence 16.9%) had an additional aneurysm, rising to about one in four if the patient had a popliteal artery aneurysm — supporting screening for other aneurysms. (van Laarhoven et al., Eur J Vasc Endovasc Surg, 2021) [4]
Evidence for stent grafts in aneurysms without symptoms is thin. A Cochrane review found a single randomized trial of 30 asymptomatic popliteal aneurysms: 1-year primary patency was 93.3% with an endovascular stent graft versus 100% with open surgery (risk ratio 0.94; 95% CI 0.78–1.12), while hospital stay (4.3 vs 7.7 days) and operating time (75.4 vs 195.3 minutes) were shorter with the stent graft. (Joshi et al., Cochrane Database Syst Rev, 2019) [5]
Popliteal Artery Aneurysm at a Glance
Aspect | Summary |
Definition | An irregular bulge in the wall of the artery behind the knee joint |
Category | A type of lower extremity aneurysm |
Frequency | Rare; more common in men than women |
First symptom | Often pain in the lower leg with walking (claudication) |
Other symptoms | Knee pain, lower leg pain, swelling behind the knee, pulsing feeling behind the knee |
Main causes | Atherosclerosis, high blood pressure, wear and tear from repeat knee use |
Biggest complication | Blood clots cutting off blood flow — can lead to loss of the limb |
Rupture risk | Possible, but rare |
Diagnostic tests | Physical exam, duplex ultrasound, CT angiography, MR angiography |
Surgery threshold | Usually performed for symptomatic aneurysms or those 2 cm (0.8 in) or larger |
Important screening | Anyone with a popliteal artery aneurysm should be screened for abdominal aortic aneurysm (AAA) |
What Is a Popliteal Artery Aneurysm?
A popliteal artery aneurysm is an irregular bulge that occurs in the wall of the artery located behind the knee joint. The popliteal artery is the main blood vessel that carries blood through the back of the knee to the lower leg and foot.
This condition is a type of lower extremity aneurysm — an aneurysm that forms in an artery of the leg rather than in the brain, chest, or abdomen.
Like all aneurysms, it begins as a ballooning in a weak spot in an artery wall. Over time, blood pressure against that weakened wall can cause the bulge to grow.
What are the symptoms of a popliteal artery aneurysm?
You might not notice any symptoms at all. When symptoms do appear, the first symptom may be pain in the lower leg that occurs with walking, called claudication.
Other symptoms of a popliteal artery aneurysm include:
Knee pain
Lower leg pain
Swelling behind the knee
A pulsing feeling behind the knee
What Causes It?
An aneurysm is a ballooning in a weak spot in an artery wall. Several different things can cause the popliteal artery wall to become weak:
Cause | How It Weakens the Artery |
Atherosclerosis | Buildup inside the arteries damages the vessel wall |
High blood pressure | Constant elevated pressure wears down the artery |
Wear and tear of the popliteal artery | Repeated use of the knee joint gradually stresses the vessel |
What are the risk factors for a popliteal artery aneurysm?
Popliteal artery aneurysms are rare. They are more common in men than in women.
An important pattern doctors watch for: this condition often occurs in men who also have an abdominal aortic aneurysm (AAA) — a swelling of the wall of the body's main artery, the aorta. That's why anyone diagnosed with a popliteal artery aneurysm should be screened for AAA.
Risk Factor | Details |
Growing older | Risk increases with age |
Being male | More common in men than women |
Smoking | Damages blood vessels |
High blood pressure | Weakens artery walls over time |
Narrowing of a heart valve | Listed as an associated risk factor |
Three or more aneurysms anywhere in the body | Having multiple aneurysms raises risk |
What complications make a popliteal artery aneurysm different?
Popliteal artery aneurysms behave differently from brain or aortic aneurysms. The most important complication is blood clots — clots can form inside the bulge and cause a severe lack of blood flow in the lower leg.
A severe lack of blood flow may produce these warning signs:
Warning Sign | What It Looks Like |
Skin color change | The affected area changes color |
No pulse | No pulse can be felt behind the knee |
Cold skin | Skin in the affected area feels cold |
Numbness | Numbness develops in the leg |
Movement loss | Inability to move the foot |
If blood flow loss becomes severe enough, it may result in loss of the limb. That's why the warning signs above deserve immediate medical attention.
On the other hand, rupture — the feared event with other aneurysms — is different here: the aneurysm may rarely rupture, but the risk of rupture is low. The everyday threat is the clot, not the blowout.
How can you prevent a popliteal artery aneurysm?
Not smoking, eating a nutritious diet and getting regular exercise can help prevent the blood vessel damage that leads to a popliteal artery aneurysm. Following a heart-healthy lifestyle can help prevent heart disease and blood vessel damage:
Do not smoke
Eat a nutritious diet
Get regular exercise
How Is It Diagnosed?
A popliteal artery aneurysm is diagnosed with a physical exam of the legs and questions about your health history, followed by imaging tests to confirm it.
Physical Exam
To diagnose a popliteal artery aneurysm, a healthcare professional usually starts with a physical exam and checks the legs for:
Swelling
Tenderness
Changes in skin color or temperature on the lower leg and behind the knee
You may also be asked questions about your medical history and health habits, such as smoking.
Imaging Tests
Imaging tests confirm the diagnosis:
Test | How It Works |
Duplex ultrasound | Uses sound waves to see how blood flows through the arteries and veins. A simple and quick way to diagnose a popliteal artery aneurysm — a hand-held ultrasound device is gently moved on the skin behind and around the knee |
CT angiography | Takes detailed images of blood flow in the arteries after a dye called contrast is injected into a blood vessel |
MR angiography | Uses magnetic resonance imaging to capture the same detailed artery images with contrast dye |
How is a popliteal artery aneurysm treated?
Treatment of a popliteal artery aneurysm depends on three factors: the size of the aneurysm, the symptoms, and your age and overall health.
Approach | When It's Used | What Happens |
Regular health checkups | Particularly if the aneurysm is small | Frequent checkups and ultrasound tests to monitor the aneurysm |
Medicines | For most people with the condition | Aspirin or another blood thinner is usually prescribed; medicines may be given through a vein; blood pressure and cholesterol medicine may be added if you have symptoms of heart disease |
Surgery | Any sized aneurysm that is causing symptoms; usually for any aneurysm that is 2 centimeters (0.8 inches) or larger | Open surgery repairs the damaged artery |
Endovascular repair | Sometimes, as a less invasive alternative | A stent is placed inside the popliteal artery to hold it open |
How should you prepare for a popliteal artery aneurysm appointment?
Preparing for a popliteal artery aneurysm appointment means noting your symptoms, medical history, smoking habits, medicines and questions to ask.
Your symptoms — especially any pain in your lower leg while walking, swelling behind the knee, or pulsing sensation
Your medical history — including any previous aneurysms or heart valve problems
Your habits — whether you smoke or have a history of smoking
All medicines, vitamins, and supplements you take, including dosages
Questions to ask your healthcare professional
Questions to Ask
How large is my popliteal artery aneurysm?
Is it causing symptoms that need treatment now?
Should I have open surgery or endovascular repair?
Do I need a blood thinner, and for how long?
Should I be screened for an abdominal aortic aneurysm (AAA)?
How often should I return for ultrasound monitoring?
Be sure to ask all the questions you have.
What Your Doctor Will Ask
Do you feel pain in your lower leg when walking?
Is there swelling, pulsing, or pain behind your knee?
Have you noticed color or temperature changes in your lower leg or foot?
Do you smoke?
Do you have high blood pressure or heart valve problems?
Have you ever been diagnosed with an aneurysm anywhere else?
Frequently Asked Questions
What is a popliteal artery aneurysm?
A popliteal artery aneurysm is an irregular bulge in the wall of the artery located behind the knee joint. It is a type of lower extremity aneurysm — one that forms in a leg artery rather than in the brain or abdomen.
What are the symptoms of a popliteal artery aneurysm?
You might not notice any symptoms at all. The first symptom may be pain in the lower leg that occurs with walking, called claudication. Other symptoms include knee pain, lower leg pain, swelling behind the knee, and a pulsing feeling behind the knee.
What causes a popliteal artery aneurysm?
An aneurysm is a ballooning in a weak spot in an artery wall. In the popliteal artery, the wall can weaken from atherosclerosis, high blood pressure, or wear and tear of the artery due to repeat use of the knee joint.
How serious is a popliteal artery aneurysm?
The condition is serious mainly because of blood clots, not rupture. Clots can cause a severe lack of blood flow in the lower leg, and severe blood flow loss may result in loss of the limb. The risk of rupture itself is low.
When is surgery needed?
Open surgery to repair the damaged artery is generally recommended for any sized popliteal artery aneurysm that is causing symptoms. Surgery is usually performed for any aneurysm that is 2 centimeters (0.8 inches) or larger. Sometimes a less invasive endovascular repair with a stent may be done instead.
Why should I be screened for an abdominal aortic aneurysm?
Popliteal artery aneurysms often occur in men who also have an abdominal aortic aneurysm (AAA), a swelling of the body's main artery. Because the two conditions frequently occur together, anyone diagnosed with a popliteal artery aneurysm should be screened for AAA.
How can I reduce my risk of developing an aneurysm?
Smoking and high blood pressure increase the risk of blood vessel problems that lead to popliteal and other aneurysms. A heart-healthy lifestyle helps: do not smoke, eat a nutritious diet, and get regular exercise.
Can a popliteal artery aneurysm affect both legs?
Yes. These aneurysms often occur behind both knees, so your provider will usually check the other leg with an ultrasound too.
Can a popliteal aneurysm be felt?
Sometimes. A provider may feel a strong, wide pulse or a pulsing lump behind the knee during an exam. Smaller aneurysms may not be felt and are found on ultrasound.
What does surgery for a popliteal aneurysm involve?
Options include open bypass surgery, which reroutes blood around the aneurysm with a vein or graft, and endovascular repair, which places a stent graft through a small puncture. A vascular surgeon will suggest the best choice for you.
Conclusion
The three lessons to carry away from this guide:
A pain in the leg while walking is a signal, not a nuisance: claudication — lower leg pain that comes on with walking — may be the first sign of a popliteal artery aneurysm, and swelling or a pulsing feeling behind the knee deserves an ultrasound check.
The real danger is the clot, not the rupture: unlike other aneurysms, this one threatens the leg through blood clots that can starve the lower leg of blood flow — cold skin, numbness, color change, no pulse, or a foot you can't move are emergency warning signs.
One diagnosis should trigger a second check: because popliteal artery aneurysms often travel together with abdominal aortic aneurysm, a diagnosis of one should lead to screening for the other.
This guide has walked you through what a popliteal artery aneurysm is, its symptoms and causes, who is at risk, the complication that matters most, the simple ultrasound that confirms it, and the treatment path from watchful waiting to surgery and stents. If your knee has been acting up while you walk, this is the condition worth ruling out.
If you want to understand aneurysms in other parts of the body, explore our complete guides to aortic aneurysm and abdominal aortic aneurysm.
Disclaimer: This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
Related Reading
Abdominal Aortic Aneurysm (AAA): Complete Guide to Symptoms, Causes, Screening, and Treatment Options explains the belly aneurysm often found alongside a popliteal aneurysm.
Popliteal Artery: Function, Anatomy, Conditions and Warning Signs explains the artery behind the knee and its warning signs.
Peripheral Artery Bypass: Restoring Blood Flow to the Limbs explains bypass surgery that reroutes blood flow around a blocked leg artery.
Acute Limb Ischemia: When a Sudden Blood Clot Cuts Off a Limb's Blood Supply — Symptoms, Treatment, and the 6-Hour Window explains the emergency when a clot suddenly cuts off blood to a limb.
References
Mayo Clinic Staff. Popliteal artery aneurysm - Symptoms and causes. Mayo Clinic. September 23, 2026. https://www.mayoclinic.org/diseases-conditions/popliteal-artery-aneurysm/symptoms-causes/syc-20355432
Mayo Clinic Staff. Popliteal artery aneurysm - Diagnosis and treatment. Mayo Clinic. September 23, 2026. https://www.mayoclinic.org/diseases-conditions/popliteal-artery-aneurysm/diagnosis-treatment/drc-20528724
Beuschel B, et al. A systematic review and meta-analysis of treatment and natural history of popliteal artery aneurysms. J Vasc Surg. 2022;75(1S):121S-125S.e14. PMID 34058308. https://doi.org/10.1016/j.jvs.2021.05.023
van Laarhoven CJHCM, et al. Systematic Review of the Co-Prevalence of Arterial Aneurysms Within the Vasculature. Eur J Vasc Endovasc Surg. 2021;61(3):473-483. PMID 33288435. https://doi.org/10.1016/j.ejvs.2020.10.002
Joshi D, et al. Endovascular versus open repair of asymptomatic popliteal artery aneurysm. Cochrane Database Syst Rev. 2019;12(12):CD010149. PMID 31868929. https://doi.org/10.1002/14651858.CD010149.pub3
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