Aberrant Right Subclavian Artery: Symptoms, Causes, Diagnosis, and Treatment
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: September 2026
Editorial note: This article is for educational purposes only and is not a substitute for professional medical advice. Unexplained chest pain, breathing difficulty, trouble swallowing, or GI bleeding should be evaluated by a healthcare professional without delay. Information reflects current published clinical sources as of August 2026.
TL;DR
An aberrant right subclavian artery (ARSA) is a congenital — present at birth — variation in blood vessel anatomy. Instead of starting on the right side of the chest like most people's, the artery that feeds the right arm and right side of the head originates farther down the aortic arch on the left, then travels back across the chest. It affects an estimated 1 in 100 people, making it the most common aortic arch variation present at birth. Many people never have symptoms. When the artery presses on the windpipe or esophagus, it can cause chest pain, noisy breathing, shortness of breath, or trouble swallowing. Treatment ranges from watchful monitoring with routine imaging to surgery that reroutes blood flow.
Quick Answer: What is an aberrant right subclavian artery?
The right subclavian artery starts on the left side of the chest instead of the right — it is a blood vessel variation present at birth. It affects about 1 in 100 people, making it the most common aortic arch anatomy change present at birth. Most people have no symptoms; when it presses on the trachea or esophagus, it can cause chest pain, noisy breathing, shortness of breath, or trouble swallowing. CT angiography is the gold-standard diagnostic test; treatment is either routine imaging surveillance or surgery to reroute blood flow.
What Is an Aberrant Right Subclavian Artery?
An aberrant right subclavian artery (ARSA) is a change to your blood vessel anatomy that is present at birth. It means your right subclavian artery starts on the left side of your chest rather than the expected right side. This artery supplies blood to the upper right side of your body.
Normally, it starts from the first major branch of your aortic arch. But with an ARSA, it starts farther down your aorta as a direct branch. With an ARSA, the right subclavian artery comes out of the aortic arch just beyond where your left subclavian artery starts.
Even though it's on your left, an aberrant right subclavian artery still must supply blood to your right arm and the right side of your neck and head. So, it must travel back toward that side. Along the way, it passes your windpipe (trachea) and esophagus. This may cause no problems. But in some cases, the artery loops around or presses on these structures. This can cause symptoms, like trouble breathing or swallowing.
It's also possible for the right subclavian artery to be wider than expected at its base, where it connects to the aorta.
Experts estimate that 1 in 100 people have an aberrant right subclavian artery. It's the most common change to aortic arch anatomy that's present at birth.
Feature | Normal anatomy | ARSA |
|---|---|---|
Where the right subclavian artery starts | First major branch of the aortic arch (brachiocephalic trunk) | Farther down the aorta, as a direct branch |
Position | Right side of the chest | Left side of the chest, traveling back to the right |
Route | Direct to right arm | Crosses past the trachea and esophagus |
How common | Typical anatomy | Estimated 1 in 100 people |
What Are the Symptoms?
Many people with an ARSA have no symptoms. Others have them in infancy or childhood. You may also feel fine for many years, but then develop symptoms as you get older.
The most common symptoms are chest pain or discomfort, noisy breathing (stridor), shortness of breath (dyspnea), and trouble swallowing (dysphagia).
Symptom | What it involves |
|---|---|
Chest pain or discomfort | Pressure sensation in the chest |
Noisy breathing (stridor) | High-pitched sound from airway narrowing |
Shortness of breath (dyspnea) | Difficulty getting enough air |
Trouble swallowing (dysphagia) | Pressure on the esophagus from the artery |
What Causes an Aberrant Right Subclavian Artery?
Changes that occur early in fetal development cause an aberrant right subclavian artery. Normally, certain fetal blood vessels go away and others remain. In babies born with ARSA, vessels along the aortic arch don't develop in expected ways. This affects how the aortic arch looks and where branch vessels begin.
Is It Hereditary?
Experts don't know if ARSA is due to gene changes or passed down within families. But some babies born with the condition also have genetic disorders, like Down syndrome. More research is needed to understand the links between ARSA and our genes.
What Are the Possible Complications?
Having an aberrant right subclavian artery raises your risk for problems with your aorta and its branch arteries. Knowing these complications is why imaging follow-up matters even when you feel fine.
Complication | What happens |
|---|---|
Aortic dissection | A tear in your aorta |
Thoracic aortic aneurysm | A bulge in the part of your aorta that runs through your chest |
Artery base rupture | A rupture in the wide base of your right subclavian artery |
Arterio-esophageal fistula | Gastrointestinal bleeding resulting from erosion into the food pipe — life-threatening |
Upper limb ischemia | A blood clot forms within the enlarged ARSA and travels to your arm, causing sudden-onset pain, weakness, and tingling (paresthesia) |
How Is It Diagnosed?
Healthcare providers sometimes diagnose an ARSA through prenatal ultrasound. Other times, it might be an unplanned finding on a test you have done for other reasons. In some cases, you don't know you have an ARSA until you start having symptoms.
One important clue: your provider may notice different blood pressure measurements between your two arms.
If you develop signs or symptoms, a provider will run tests to find the cause. Tests that commonly diagnose an aberrant right subclavian artery include an echocardiogram and a barium swallow test. CT angiography is the gold-standard test. MRI angiography is used as an alternative if you're allergic to iodinated contrast.
Test | Role |
|---|---|
Prenatal ultrasound | Can detect ARSA before birth |
Blood pressure check (both arms) | A difference between arms can signal ARSA |
Echocardiogram | Ultrasound imaging of the heart and vessels |
Barium swallow test | X-ray imaging of swallowing function |
CT angiography | The gold-standard test |
MRI angiography | Alternative when iodinated contrast causes allergy |
How Is an Aberrant Right Subclavian Artery Treated?
An aberrant right subclavian artery doesn't always need treatment. It depends on your symptoms and risk of complications.
If you don't have symptoms, your healthcare provider may monitor your condition over time. This means they'll ask you to come in for routine imaging tests. These allow your provider to check for any changes or problems with your aorta and its branches.
You may need surgery if imaging tests reveal concerns or if you develop symptoms. The exact details of the surgery vary based on your symptoms and anatomy. In general, surgery reroutes blood flow to relieve pressure on your esophagus or trachea. Your surgeon can also repair damaged areas of your blood vessels. Your surgeon will tailor the technique to your needs.
Approach | How it works | Best suited for |
|---|---|---|
Watchful monitoring | Routine imaging tests over time | No symptoms; complication risk low |
Open surgery | Usually an incision between the ribs rather than down the middle of the chest; some people need a sternotomy | Symptoms or anatomy that need direct repair |
Hybrid approach | A mix of open and less invasive (endovascular) surgery; creates a new route for blood flow and repairs aortic damage | People with a thoracic aortic aneurysm |
When Should You See Your Healthcare Provider?
Contact a provider if you have symptoms that concern you. If you get an ARSA diagnosis, your provider will tell you how often you need to come in for check-ups or testing. They'll also explain the timeline for your recovery and follow-up visits.
What Is the Outlook?
In most cases, surgery can relieve your symptoms and lower your risk of complications. It's important to keep all of your appointments and let your provider know if you start having symptoms again.
An aberrant right subclavian artery isn't a diagnosis you hear about every day. And maybe the last thing you expected was to learn that you have it. But now that you know, you can do something about it. This might simply mean seeing your healthcare provider for routine visits, or it might mean surgery to help you feel better and avoid issues down the road. Each person with ARSA is different. Your care team will explain what's best in your case.
Conclusion: Most Sore Throats and Chest Twinges Aren't ARSA — But Know the Signal
An aberrant right subclavian artery is the most common birth variation of aortic arch anatomy — about 1 in 100 people have it. For most, it is a silent finding discovered on a prenatal scan or an imaging test ordered for another reason. Because the artery takes an unusual route from the left side of the chest to the right arm, the main thing to watch is whether it presses on your windpipe or esophagus.
When it does, the signal is unmistakable: chest pain, noisy breathing, shortness of breath, or trouble swallowing. The good news is that modern imaging — especially CT angiography — maps the anatomy precisely, and surgery can reroute blood flow, relieve that pressure, and lower the risk of serious complications like aneurysm or fistula.
If you or your child has been diagnosed with ARSA, the single most important habit is keeping your follow-up imaging schedule. Even a symptom-free ARSA deserves periodic eyes on the aorta.
Have unexplained trouble swallowing, noisy breathing, or blood pressure readings that differ between your arms? Ask your healthcare provider whether imaging of the aortic arch — starting with a CT angiogram — is warranted, and bring any previous scan reports to that appointment.
Frequently Asked Questions
1. What is an aberrant right subclavian artery? A congenital variation where the right subclavian artery — the vessel feeding the right arm and right side of the head — originates on the left side of the aortic arch instead of the right, then travels back across the chest to reach its destination.
2. How common is it? About 1 in 100 people have an ARSA, making it the most common aortic arch anatomy change present at birth.
3. Does it cause symptoms? Often not. Many people never have symptoms. When the artery presses on the trachea or esophagus, it can cause chest pain, noisy breathing (stridor), shortness of breath, or trouble swallowing — in infancy, childhood, or later in life.
4. Is it hereditary? It is not yet known whether ARSA comes from gene changes or runs in families. Some babies with ARSA also have genetic conditions such as Down syndrome, and more research is needed.
5. How is it diagnosed? Sometimes prenatally by ultrasound, or as an unplanned finding on imaging. Key tests include echocardiogram and barium swallow, with CT angiography as the gold-standard test. MRI angiography is an alternative for contrast allergy. Different blood pressure readings between the two arms can also be a clue.
6. Does it always need treatment? No. If you have no symptoms, providers often monitor with routine imaging. Surgery is considered when symptoms develop or imaging reveals concerning changes.
7. What does surgery involve? Surgery reroutes blood flow to relieve pressure on the esophagus and trachea and repairs any damaged vessels. It is usually done through an incision between the ribs (occasionally a sternotomy), or as a hybrid open-plus-endovascular approach — especially helpful when a thoracic aortic aneurysm is present. In most cases, surgery relieves symptoms and lowers complication risk.
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