S2. Subclavian Artery Disease

Subclavian Artery Disease

The subclavian arteries are pipes that carry blood rich in oxygen from your heart to your arms and the back of your brain. Subclavian artery disease develops when blood flow is decreased because a section of one of these arteries has become narrow or is blocked. This blockage is often caused by the buildup of plaque—fat, cholesterol and other substances—also called atherosclerosis.

If you have subclavian artery disease, you have a higher chance of developing this buildup in other arteries throughout your body, which can lead to a heart attack, chest pain, stroke or cramping (claudication) in the legs. In some cases, the blockage can be caused by birth defects, radiation exposure, or pressure on the artery from outside sources.

Subclavian artery disease is a form of peripheral arterial disease (PAD), which involves blockages in arteries outside of your heart. However, the blood vessels of the upper body are affected less often. About 3% of the general population has subclavian artery disease, and in those with PAD, the percentage is 11%.

Often, subclavian artery disease does not cause any symptoms because the disease progresses slowly or the body creates blood vessels around the blockage to maintain flow—or both. The symptoms that do occur are tied to the area that is blocked. You may experience arm pain or muscle fatigue when using your arms above your head, or doing any activity that demands more oxygen-rich blood flow to the arms. Other symptoms can include:

  • Dizziness (vertigo) with arm activity
  • Feeling as if you might pass out
  • Blurred, double or partial loss of vision

Your health care professional may suspect subclavian artery disease if the top number of your blood pressure differs greatly between both arms (more than 20 mm Hg). The pulses in both of your arms will be compared as well as the temperature of your skin. In severe cases, your fingers may change colors and have pain without activity. Imaging tests to examine the blood flow in the subclavian artery and lab work often will be ordered.

Use this condition center to learn more about subclavian artery disease, how it’s treated and for help preparing questions to ask during your next health visit.



Subclavian artery disease is often caused by a buildup of plaque—fat, cholesterol and other substances (also called atherosclerosis)—in one of the subclavian arteries. There are two of these: a right subclavian artery and a left subclavian artery that supply blood to your upper body.

The left subclavian artery branches off of the aorta, which is a large blood vessel that starts at the heart and travels into the abdomen. Another artery branches off the aorta on the right (called the brachiocephalic artery) and divides into the right subclavian artery and the right common carotid artery.

Other causes of subclavian artery disease include:

  • Inflammation of the arteries
  • Fibromuscular dysplasia (a disease that causes abnormal cell or tissue buildup in the wall of the artery)
  • Radiation exposure to the neck, chest or both
  • Birth defects
  • Neurofibromatosis (growth of tumors on nerve tissue)
  • Trauma

Only a few signs aid your physician in diagnosing this condition. A lower blood pressure reading when using the arm on the side where the artery is blocked is a strong sign of subclavian artery disease. If your health professional suspects you have a blockage, it is important to have your blood pressure checked in both arms. Any consistent blood pressure difference greater than 20 mm Hg suggests subclavian artery disease.

The presence of a harsh noise heard with a stethoscope over the blood vessel involved can be another sign of disease and obstruction.

If you have subclavian artery disease, the symptoms you experience depend largely on the artery involved and the degree of blockage. Symptoms may reflect a lack of blood flow to the area being supplied, such as:

  • Arm or hand pain with activity (claudication)
  • Numbness (paresthesia)
  • Pain while resting
  • Discoloration of the fingers, hands and/or arm

Some patients don’t have symptoms because the body adapts in response to the obstruction and can create new blood vessels that go around the blockage.
When the artery that branches from the subclavian artery and supplies the back of the brain is affected, you may experience symptoms of less blood flow to the back of the brain. You may have dizziness, a hard time walking or poor balance.

Exercising the arm affected by the narrowed subclavian artery causes more blood to be sent to the arm instead of the brain. This is called subclavian steal syndrome. Your health care professional may suspect this syndrome if when using your arms you experience:

  • Lightheadedness
  • Fainting (syncope)
  • Dizziness (vertigo)
  • Difficulty walking
  • Blurred or double vision
  • Arm tiredness or discomfort

Some simple tests may help identify this syndrome.

What Increases Your Risk

The risk for developing subclavian artery disease is similar to the risk for atherosclerosis, or plaque (made up of cholesterol, fatty substances and calcium) buildup in the walls of other blood vessels of the body, such as the heart (coronary artery disease), legs (peripheral arterial disease) and neck (carotid artery disease). The following increases your risk:

  • Tobacco abuse
  • High cholesterol
  • Longstanding high blood pressure
  • Other atherosclerotic (or plaque) disease (for example CAD, PAD)
  • Obesity
  • Sedentary lifestyle
  • Family history

On rare occasions, a bony abnormality you may have been born with can cause a blood vessel to compress (for example an extra rib). Younger age groups and some athletes are susceptible to this condition.

When to Call a Doctor

Subclavian artery disease, particularly related to the buildup of plaque, often has no symptoms. However, it’s a good idea to talk with your health care professional if you have the following:

  • When you take blood pressure in your left and right arms, there is always a difference of more than 20 mm Hg in your systolic blood pressure readings (upper number).
  • You notice cramps in your arm(s) when you raise your hands above your head or perform activities with your arms raised.
  • You notice dizziness (vertigo) or vision problems when you raise your arms or perform activities with your arms raised.
  • Your hand becomes cold, pale and painful, and you have a weak pulse compared to your other arm.
  • If you have had coronary artery bypass surgery and the left internal mammary artery (LIMA) was used as a graft and you notice chest pains particularly while performing activities with your left arm. Significant blockage in the subclavian artery can cause angina with arm activity. Less blood flows down the graft because the blockage occurs before the graft.

Exams and Tests

Your health care professional will take your blood pressure using both your right and left arms. Then he or she will compare the top number (systolic blood pressure). He or she also may take your pulses and listen to them with a stethoscope.

Another good test to find out whether there is narrowing in your arteries is to do an ultrasound. This test is painless and without any risk. It may take about 30 to 45 minutes. Sometimes, this test may not give good images of the arteries under the chest bone. For imaging of those arteries in the chest, a CT scan with contrast or an MRI with contrast may be requested.

These tests will give your health care team a very good idea about whether you have a blockage and how severe it is. In rare cases, an angiogram may be needed. In this test, a small tube called a catheter is placed inside a blood vessel in your wrist or groin and then moved to the area to be studied to take pictures and measure the pressure across the blockage.


The main treatment for subclavian artery disease involves medical therapy and lifestyle changes. As subclavian artery blockages are usually caused from atherosclerosis, your health care professional may prescribe aspirin and cholesterol-lowering medications. These medicines can prevent the plaque buildup from getting worse over time.

At the same time, it is important to target other factors that can lead to plaque buildup. Smoking, or any nicotine use, should be stopped. If you smoke, quit. Controlling blood pressure and diabetes is important as well because both of these conditions are strongly linked to the risk of building up plaque. Following a heart-healthy diet and taking part in a regular exercise program are also very good habits to pick up.

Despite these treatments, many people with subclavian artery disease will experience symptoms such as arm fatigue, arm pain, or dizziness. In these instances, your health care professional may recommend treating the blockages with either angioplasty using stents or surgery. Stenting is a nonsurgical, less invasive technique that involves inserting a small tube called a catheter through an artery in the arm or leg. Through the catheter, a stent is placed across the blockage to restore normal flow.

Most subclavian blockages can be treated with stents, but in some cases, surgery may be needed. With surgery, blood flow is rerouted across the blockage using a small plastic tube called a bypass graft. Both stents and surgery are highly effective treatments and often help symptoms improve.

Living With Subclavian Artery Disease

If you have subclavian artery disease, you may experience weakness or pain in your arm on the affected side, dizziness, or blurred or double vision.

As atherosclerosis can develop in any of the arteries of the body, individuals living with subclavian artery disease should look out for symptoms of shortness of breath or chest pain when being active because this may be a sign of coronary artery disease. If your walking is limited because of leg fatigue, cramping or pain, it may be because of peripheral artery disease (PAD). If you develop these symptoms, talk to your doctor.

If your doctor has decided to monitor the disease, you should tell him or her if you have any worsening or new symptoms. Also your health care professional may check your blood pressure in both arms and conduct ultrasound tests routinely to watch the narrowing in your arteries. These tests would also be done if you have an angioplasty or surgery.


You can reduce your risk of subclavian artery disease caused by atherosclerosis by keeping your blood vessels healthy. It is important to pay attention to the factors that contribute to the disease. Modifiable risk factors—in other words the risk factors that can be controlled—to prevent subclavian artery disease include:

  • Tobacco use:If you smoke tobacco, please consult with your health care provider about ways to quit. Use of any tobacco product increases your blood pressure and promotes the formation of plaques within the blood vessels. There are many aids, and even apps, now available to help you quit.
  • Sedentary lifestyle:Be active and maintain a healthy weight. In general, individuals should take part in at least 30 minutes of moderate-level aerobic exercise per day at least five days per week.
  • Diabetes:If you are unsure whether you have diabetes, speak with your provider about how to be screened. And, if you have diabetes, it is important to take steps to control your blood sugar by ensuring that your hemoglobin A1c is <7%. Elevated blood sugars over time can damage the inside of your blood vessels and lead to atherosclerosis.
  • High cholesterol:Consult with your doctor to find out whether you need a lipid (cholesterol) panel. If you don’t reach your goal cholesterol number despite eating a healthy diet and exercising regularly, your doctor may prescribe lipid-lowering medicine, such as statins.
  • Unhealthy diet:A healthy diet is an effective means of preventing atherosclerotic cardiovascular diseases. This includes: three to five servings of vegetables and two servings of fruit per day; two servings of fish high in omega-3-fatty acids per week; four handfuls of almonds and/or walnuts per week; use of healthy oils like olive and canola; and picking whole grains over refined.