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Thoracic Outlet Syndrome

  • Cynthia M. Johnson, MA
Publication Type:


Thoracic Outlet Syndrome



The thoracic outlet is the site of the lower neck and upper chest. It has a many nerves, blood vessels, muscles, and bones that run through a small site. Thoracic outlet syndrome (TOS) is when the nerves and blood vessels are squeezed, irritated, or harmed.

Thoracic Outlet Syndrome.

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TOS may be due to:

  • Defects in nearby structures
  • Trauma
  • Poor posture

Risk Factors

Your risk of TOS is raised if you have:

  • An extra rib or a first rib that is not typical
  • Trauma
  • Motions that you repeat often
  • Job problems, such as poor posture or using the computer too much


TOS may cause:

  • Arm or hand pain
  • Lack of arm or hand strength
  • Numbness and a feeling of pins and needles
  • Cold sensitivity in the hands and fingers
  • Pain or sores of the fingers
  • Poor blood flow to the arm, hands, and fingers
  • Swelling
  • Skin of arm turning pale and blue


Your doctor will ask about your symptoms and health history. A physical exam will be done.

Your doctor will ask you to hold your arms and head in positions that may cause TOS. The results of these tests will help show whether you have TOS.

You may also have:

Pictures may be taken with:


Treatment depends on the symptoms that you have. In most cases, TOS is treated with pain medicine and physical therapy.


TOS can’t be prevented.





  • Fugate MW, Rotellini-Coltvet L, Freischlag JA. Current management of thoracic outlet syndrome. Curr Treat Options Cardiovasc Med. 2009 Apr;11(2):176.
  • Povelson S, Povlsen B. Diagnosing thoracic outlet syndrome: current approaches and future directions. Diagnostics (Basel). 2018;8(1):pii E21.
  • Thoracic outlet syndrome. Ortho Info—American Academy of Orthopaedic Surgeons website. Available at: http://orthoinfo.aaos.org/topic.cfm?topic=a00336.
  • Thoracic outlet syndrome. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T115626/Thoracic-outlet-syndrome .
  • Thoracic outlet syndrome. National Institute of Neurological Disorders and Stroke website. Available at: https://www.ninds.nih.gov/Disorders/All-Disorders/Thoracic-Outlet-Syndrome-Information-Page.
  • Vanti C, Natalini L, Romeo A, Tosarelli D, Pillastrini P. Conservative treatment of thoracic outlet syndrome. A review of the literature. Eura Medicophys. 2007 Mar;43(1):55.


  • Daniel A. Ostrovsky, MD
Last Updated:

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.