Thoracic Outlet Syndrome
Pronounced: tho-RASS-ik OUT-let SYN-drome
by Cynthia M. Johnson, MA
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.
TOS may be due to:
Your risk of TOS is raised if you have:
TOS may cause:
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.
You may need to take:
A therapist will make an exercise plan. It will help to ease symptoms by relaxing nearby muscles, making your posture better, and easing pressure on nerves and blood vessels.
You may need to:
If other treatments fail, your doctor may advise surgery. The goal is to move or remove the source of the pressure. In some people, this may mean taking out part or all of the first rib. This can make more room for the nerves and blood vessels.
TOS can’t be prevented.
Occupational Safety and Health Administration
The Nicholas Institute of Sports Medicine and Athletic Trauma
Canadian Centre for Occupational Health and Safety
Public Health Agency of Canada
Crotti FM, Carai A, Carai M, et al. TOS pathophysiology and clinical features. Acta Neurochir Suppl. 2005;92:7-12.
Huang JH, Zager EL. Thoracic outlet syndrome. Neurosurgery. 2004;55(4):897-902.
Nord KM, Kapoor P, Fisher J. False positive rate of thoracic outlet syndrome diagnostic maneuvers. Electromyogr Clin Neurophysiol. 2008;48(2):67-74.
Povelson S, Povlsen B. Diagnosing thoracic outlet syndrome: current approaches and future directions. Diagnostics (Basel). 2018;8(1):pii E21.
Sanders RJ, Hammond SL, Rao NM. Diagnosis of thoracic outlet syndrome. J Vasc Surg. 2007;46(3):601-604.
Thoracic outlet syndrome. Ortho Info—American Academy of Orthopaedic Surgeons website. Available at:
...(Click grey area to select URL)
Updated March 2018. Accessed June 25, 2018.
Thoracic outlet syndrome. EBSCO DynaMed Plus website. Available at: http://www.dynamed... . Updated December 22, 2014. Accessed June 25, 2018.
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. Accessed June 25, 2018.
Wehbe M, Leinberry C. Current trends in treatment of thoracic outlet syndrome. Hand Clin. 2004;20(1):119-121.
Last reviewed May 2018 by EBSCO Medical Review Board Rimas Lukas, MD
Last Updated: 6/25/2018
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