Thoracic Outlet Syndrome

The subclavian artery runs through the thoracic outlet. Pressure on this artery can limit blood flow into your arm, leading to symptoms that may include:

• Abnormal color in your hand and fingers
• Hand and fingers that feel cold or weak
• Reduced range of motion
• Swelling or numbness in your arm and hand

This form of the condition affects the nerves. If you have thoracic compression of the nerves, you may experience:

• Discoloration of the hand
• Hand weakness
• Pain in the neck, shoulder, arm or hand
• Pins and needles or cold feeling in the hand and fingers

Squeezing of the subclavian vein can make it difficult for blood to flow out of the arm, which can lead to blood clots. Venous thoracic outlet syndrome may cause:

• Aching, swelling or tingling in the affected arm
• Arm and hand fatigue
• Difficulty finding a pulse in the arm
• Limited range of motion
• Pale skin

A variety of conditions, including rotator cuff injuries and problems with the discs at the top of the spine, can cause symptoms like those of thoracic outlet syndrome. As a result, your physician will want to gather as much information as possible to rule out other potential causes and definitively diagnose thoracic outlet syndrome.

Your physician will ask about your symptoms and how they’re affecting you. Next, they’ll conduct a physical exam to look for skin discoloration in the affected arm or hand and weakness in the hands or fingers.

During your exam, your physician may have you perform an elevated arm stress test. You’ll raise your arms above your head for several minutes and open and close your fists so your physician can see if symptoms occur.

To confirm thoracic outlet syndrome, you may require one or more of these tests:

• Ultrasound to assess blood flow in your subclavian artery and vein, which will allow your provider to see any compression or narrowing of blood vessels.
• X-ray to identify any physical abnormalities that may be compressing nerves or blood vessels in the thoracic outlet, such as an extra rib or bone spurs.
• Computerized tomography (CT) scan to see both structural abnormalities and vascular compressions. CT scans can also use contrast dye so your healthcare team can better see your blood vessels.
• Magnetic resonance imaging (MRI) scan to look at any compression or inflammation in your soft tissues, such as your muscles and ligaments.
• Arteriography is also known as an angiogram. It uses both contrast dye and X-ray imaging to visualize blood flow in your subclavian artery and can identify narrowing or blockages.
• Venography tests evaluate the subclavian vein to detect compression or blood clots associated with TOS.
• Electromyography (EMG) assesses the electrical activity of your muscles to identify any nerve disruption.
• Electromyography and nerve conduction studies to see how well the muscles and nerves in the arm and hand function.
• Imaging tests to look for problems with the bones, soft tissues and blood vessels in and around the thoracic outlet.
• Special tests for thoracic outlet syndrome that gauge blood circulation in the arm and hand.