What is thoracic outlet syndrome?

Symptoms depend on the type of TOS.

Symptoms of nerve TOS may happen when you move your arms to shoulder level or to other positions that put pressure on the nerves. These symptoms include:

• Pain, numbness, or tingling in the neck, shoulder, arm, or hand.
• Weakness in the arm or hand.
• In some cases, headaches.

Symptoms of vascular (blood vessel) TOS include:

• Sudden swelling and pain in the arm and shoulder.
• Pain and fatigue in the lower arm or hand when you hold them over your head.
• Wounds on the hands and fingers that don't heal.
• Sudden pain, weakness, numbness, or tingling in the hands.
• Cold, pale fingers.
• A bluish skin color in the arms and hands.

There are different types of TOS. The most common type is neurogenic (nerve) TOS. This is caused by nerves that are squeezed in the thoracic outlet. In vascular (blood vessel) TOS, veins or arteries are squeezed.

If your TOS is caused by squeezed nerves, you will probably have physical therapy. If your TOS involves blood vessels, you may have medicine or surgery to help blood flow normally. In either case, you may have surgery to relieve the tightness in the thoracic outlet.

Your doctor will ask about your symptoms and your past health. You will have a physical exam. You may also have a chest X-ray or another imaging test, such as an MRI, a CT scan, or an ultrasound. Sometimes, nerve studies or a shot to numb the area are done.

Try to stop or reduce activities that cause symptoms. A physical therapist can teach you exercises to help reduce symptoms. Ask your doctor if you can take an over-the-counter medicine for pain, like acetaminophen or ibuprofen. Follow the directions for medicine your doctor may prescribe. Try to stay at a healthy weight.

Thoracic outlet syndrome (TOS) is a condition in which the nerves or blood vessels are squeezed tightly in a small space behind the collarbone (clavicle). This space is called the thoracic outlet. TOS can cause pain, numbness, or weakness in your shoulder, arm, or hand. Sometimes it causes swelling.

TOS is caused by a thoracic outlet that's smaller than normal. This squeezes nerves or blood vessels. The outlet may be smaller because of the size or shape of the muscles or bones in the area. Injuries from an accident, repeated movements, or a fall can also lead to TOS.