Pronounced: tho-RASS-ik OUT-let SYN-drome
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
Copyright © Nucleus Medical Media, Inc.
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
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:
...(Click grey area to select URL)
Updated March 2018. Accessed March 17, 2020.
Thoracic outlet syndrome. EBSCO DynaMed Plus website. Available at: http://www.dynamed.com/topics/dmp~AN~T115626/Thoracic-outlet-syndrome . Updated December 22, 2014. Accessed March 17, 2020.
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 March 17, 2020.
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.
Last reviewed March 2020 by
EBSCO Medical Review Board
Daniel A. Ostrovsky, MD
Last Updated: 3/17/2020