Thoracic Outlet Syndrome Overview

LIke ThisLIke ThisLIke ThisLIke ThisLIke This

Contact the Thoracic Outlet Syndrome Program

1-617-355-9600
International: 1-617-355-5209

Thoracic outlet syndrome (TOS) is a condition whereby symptoms are produced by compression of nerves and/or blood vessels in the upper chest. The passageway for these nerves and blood vessels to exit the chest and supply the arms is referred to as the thoracic outlet. Muscle, bone, and other tissues border the thoracic outlet. Any condition that results in enlargement or movement of these tissues near the thoracic outlet can cause thoracic outlet syndrome. These conditions include muscle enlargement (such as from weight lifting), repetitive use (such as might be seen in baseball pitchers or rowers), injuries, an extra rib extending from the neck (cervical rib), and weight gain. Often no specific cause is detectable.


We know that part of the ease with which she has recovered/healed is due to her own good health and young body but we do attribute a great deal of it to your skill and caring. We so appreciate the time you took with us to thoroughly explain things prior to the surgery (especially the way that you prepared us for the worst-case scenario without instilling a great amount of fear) and in all subsequent appointments...

Dara St Sauveur


Some patients with severe or persistent symptoms can require surgical operations to open the thoracic outlet.

Diagram of Thoracic outlet syndrome (TOS):

TOSDiagram101

Generally, there are three types of thoracic outlet syndrome:

1) Neurogenic (neurological) thoracic outlet syndrome
This form of thoracic outlet syndrome is characterized by compression of the brachial plexus, a network of nerves that come from your spinal cord and control muscle movements and sensation in your shoulder, arm and hand. Neurogenic TOS can result in tingling, weakness and even mild color changes with elevation of the arm overhead. This is typically considered to be the most common type of TOS.

2) Venous thoracic outlet syndrome —
This occurs when the subclavian vein, which drains blood from the arm, is compressed as it travels under the collarbone (clavicle) and through the thoracic outlet. This can result in swelling, redness or heaviness of the arm when it is being used actively or raised overhead. In extreme cases, this can result in clotting of the vein, resulting in significant swelling and pain that is persistent. This situation is called effort thrombosis, or Paget-Schroetter disease.

3) Arterial thoracic outlet syndrome —
This occurs when the subclavian artery, supplying blood to the arm, is impinged upon by the thoracic outlet structures. This can result in loss of blood flow to the arm, resulting in a cool, white and painful arm. Often this is temporary, occurring only while the arm is raised. In severe or long-standing cases, this can result in damage to the artery or clotting of the artery, resulting in an emergency situation.

Thoracic outlet syndrome symptoms include:

  • neck pain,
  • shoulder pain,
  • arm pain,
  • numbness and tingling of the fingers,
  • impaired circulation to the extremities (causing discoloration, swelling, or pain)
Diagnosis of thoracic outlet syndrome is suggested by these symptoms as well as physical findings during a doctor’s examination. It is sometimes supported by electrical and/or radiology tests. 
We are grateful to have been ranked #1 on U.S. News & World Report's list of the best children's hospitals in the nation for the third year in a row, an honor we could not have achieved without the patients and families who inspire us to do our very best for them. Thanks to you, Boston Children's is a place where we can write the greatest children's stories ever told.”
- Sandra L. Fenwick, President and CEO

Boston Children's Hospital 300 Longwood Avenue, Boston, MA 02115 617-355-6000 | 800-355-7944

Close