Thoracic Outlet Syndrome

Your thoracic outlet is a small space just behind and below your collarbone. Thoracic outlet syndrome (TOS) is the presence of hand and arm symptoms due to pressure against the nerves or blood vessels in the thoracic outlet area.

Thoracic outlet syndrome (TOS) causes pain in the shoulder, arm, and neck. It happens when the nerves or blood vessels just below your neck are compressed, or squeezed. The compression can happen between the muscles of your neck and shoulder or between the first rib and collarbone. You may feel burning, tingling, and numbness along your arm, hand, and fingers. If a nerve is compressed, you may also feel weakness in your hand. If a vein is compressed, your hand might be sensitive to cold, or turn pale or bluish. Your arm might swell and tire easily.

TOS is more common in women. It usually starts between 20 and 50 years of age. Doctors do nerve and imaging studies to diagnose it.

There are many causes of TOS, including:
  • Injury
  • Anatomical defects
  • Tumors that press on nerves
  • Poor posture that causes nerve compression
  • Pregnancy
  • Repetitive arm and shoulder movements and activity, such as from playing certain sports

Treatment depends on what caused your TOS. Medicines, physical therapy, and relaxation might help. Surgery may also be an option. Most people recover.

Nerves coming from the spine and major blood vessels of the body pass through a narrow space near your shoulder and collarbone on the way to the arms. Sometimes, there is not enough space for the nerves to pass by through the collarbone and upper ribs.

Pressure (compression) on these blood vessels or nerves can cause symptoms in the arms or hands. Problems with the nerves cause almost all cases of thoracic outlet syndrome.

Pressure may happen if you have: 

People with this syndrome often have injured the area in the past or overused the shoulder.

People with long necks and droopy shoulders may be more likely to develop this condition because of extra pressure on the nerves and blood vessels.

Symptoms of thoracic outlet syndrome may include:
  • Pain, numbness, and tingling in the pinky and ring fingers, and the inner forearm
  • Pain and tingling in the neck and shoulders (carrying something heavy may make the pain worse)
  • Signs of poor circulation in the hand or forearm (a bluish color, cold hands, or a swollen arm)
  • Weakness of the muscles in the hand

Your health care provider will examine you and ask questions about your medical history and symptoms. 

Sometimes the following tests are done to confirm the diagnosis:
  • Electromyography (EMG)
  • CT angiogram
  • MRI
  • Nerve conduction velocity study
  • X-ray

Tests are also done to rule out other problems, such as carpal tunnel syndrome or a damaged nerve due to problems in the neck.

Physical therapy is often used to treat thoracic outlet syndrome. It helps: 

Make your shoulder muscles stronger
Improve your range of motion in the shoulder
Promote better posture 

Your health care provider may prescribe pain medicine. 

If there is pressure on a vein, your provider may give you a blood thinner to prevent a blood clot. 

You may need surgery if physical therapy and changes in activity do not improve your symptoms. The surgeon may make a cut either under your armpit or just above your collarbone.

During surgery, the following may be done:
  • An extra rib is removed and certain muscles are cut.
  • A section of the first rib is removed to release pressure in the area.
  • Bypass surgery is done to reroute blood around the compression or remove the area that is causing the symptoms. 

Your doctor may also suggest other alternatives, including angioplasty, if the artery is narrowed.

Surgery to remove the extra rib and break up tight fiber bands may ease symptoms in some patients. Surgery can be successful in more than half of patients. A few patients have symptoms that return after surgery.