Content on this page requires a newer version of Adobe Flash Player.

Get Adobe Flash player

Thoracic outlet syndrome is a condition involving compression of the nerves and/or blood vessels in the region around the neck and collarbone, called the thoracic outlet. Thoracic outlet syndrome is controversial in the medical literature. The diagnosis and treatment of patients who have thoracic outlet syndrome have been varied, particularly in those with complaints of tingling, numbness and pain in the arm and hand. Recently, surgeons have recognized that patients with thoracic outlet syndrome can be divided into patients with compression of the blood vessels and those with nerve compression. Symptoms related to nerve compression are more common than those involving compression of the blood vessels. However, most of the controversy surrounds patients with compression of the nerves (brachial plexus).

In thoracic outlet syndrome, abnormalities in insertions of the scalenus anticus and scalenus medius muscles — or simple enlargement of these muscles due to unhealthy postures — can create narrowing of the triangular region through which the brachial plexus travels across the first rib and beneath the clavicle. Illustration from Surgery of the Peripheral Nerve by Mackinnon and Dellon, reprinted with permission of Thieme Medical Publishers, Inc.


Patients with thoracic outlet syndrome related to compression of the brachial plexus usually complain of a feeling of "pins and needles" and/or numbness in the arm, forearm or hand. Many patients also have complaints of pain and aching in the shoulder, neck or shoulder blade region. These symptoms usually are made worse when the arms are positioned overhead.

Patients may describe headaches at the back of the head or around the eyes. Pressure on the blood vessels in the region of the thoracic outlet may cause the hand to feel cooler or to be swollen, or the hand may appear white or blue. Early symptoms may only occur with the arms in an overhead position and go away with the arms down by the side. As time goes on, symptoms often occur more frequently and with less time in irritating positions.

What Causes Thoracic Outlet Syndrome?

In general, thoracic outlet syndrome is thought to be caused by a number of factors, including activities at home and work, sleep postures, trauma, anatomical variations and other diseases.

Double Crush Syndrome

Patients with thoracic outlet syndrome usually have symptoms of tingling and numbness in the hand. These hand symptoms are similar to those of carpal tunnel syndrome and cubital tunnel syndrome. The “double crush” mechanism may play a role in the development of symptoms in patients with thoracic outlet syndrome. The nerve fiber begins in or near the spinal cord and then goes all the way to the hand to give sensation and movement to the arm and hand. If the nerve is pinched at one place, then it is less likely to tolerate any more pressure along the nerve. Therefore, other tight places, such as at the wrist (carpal tunnel) or elbow (cubital tunnel), are more likely to produce symptoms with very little added pressure.

Non-operative Management

In the vast majority of patients, non-operative treatment is successful in relieving the symptoms of thoracic outlet syndrome. This begins by modifying your activities to decrease the time that you spend in positions that are aggravating your symptoms.

Thoracic Outlet Surgery

Surgical management may involve release of the scalene muscles and/or removal of the first rib. This operation frequently is done with an incision above the collarbone. However, your surgeon instead may recommend a surgical approach through the armpit.

Patient information on thoracic outlet syndrome