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Thoracic Outlet Syndrome

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The thoracic outlet is the area of the lower neck and upper chest. This area has a variety of nerves, blood vessels, muscles and bones that run through a fairly small area. When the nerves and blood vessels of this area are compressed, irritated or injured they can cause a range of symptoms known as the thoracic outlet syndrome (TOS).

Thoracic Outlet Syndrome
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Compression, injury, or irritation of nerves and blood vessels can be caused by:

  • Defects in nearby structures
  • Poor posture
  • Trauma
  • Repetitive arm or shoulder movement
  • Tumors

Risk Factors

Factors that may increase your chance of developing TOS include:

  • Having an abnormal first rib
  • Poor posture
  • Repetitive motion
  • Trauma
  • Obesity


TOS may cause the following:

  • Arm or hand pain
  • Arm or hand weakness
  • Numbness and tingling
  • Cold sensitivity in the hands and fingers
  • Pain or sores of the fingers
  • Poor blood circulation to the arm, hands, and fingers
  • Swelling of the limb
  • Skin of arm turning pale and blue


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

During an elevated arm stress test, your doctor will ask you to hold your arms and head in positions that may cause the TOS symptoms to reappear. The results of these tests will help determine whether you have TOS and rule out other possible related conditions.

Other tests may include:

  • Blood tests
  • Electromyography and nerve other conduction tests

Images of internal body structures may be taken with:


Treatment varies depending on your specific symptoms. In most cases, TOS is managed with pain medication and physical therapy.


Your doctor may recommend the following:

  • Non-steroidal anti-inflammatory drugs (NSAIDs)
  • Muscle relaxers
  • Antidepressants
  • Blood thinners
  • Anti-platelet medications

Physical Therapy

A physical therapist will design some some exercises for you. The exercises will help to relieve symptoms by relaxing nearby muscles, improving posture and reducing pressure on nerves and blood vessels.

Lifestyle Changes

As part of your treatment, you may need to make lifestyle changes. Some of these may include:

  • Avoid activity that causes pain
  • Practice good posture
  • Avoid repetitive motion
  • Change your workstation layout
  • If you are overweight, talk to your doctor about how you can lose weight
  • Exercise regularly to improve strength, flexibility and range of motion


If other treatments fail, your doctor may recommend surgery. The goal of surgery is to move or remove the source of the compression. In some people, this may involve removing part or all of the first rib to make more room for the nerves and blood vessels.


There are no current guidelines to prevent TOS.

Revision Information

  • Reviewer: Rimas Lukas, MD
  • Review Date: 05/2014 -
  • Update Date: 06/02/2014 -
  • Occupational Safety & Health Administration

  • The Nicholas Institute of Sports Medicine and Athletic Trauma (NISMAT)

  • Canadian Centre for Occupational Health and Safety (CCOHS)

  • 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;55:897-902.

  • Nord KM, Kapoor P, Fisher J, et al. False positive rate of thoracic outlet syndrome diagnostic maneuvers. Electromyogr Clin Neurophysiol. 2008;48:67-74.

  • Sanders RJ, Hammond SL, Rao NM. Diagnosis of thoracic outlet syndrome. J Vasc Surg. 2007;46:601-604.

  • Thoracic outlet syndrome. American Academy of Orthopaedic Surgeons Ortho Info website. Available at: Updated January 2011. Accessed July 19, 2013.

  • Thoracic outlet syndrome. EBSCO DynaMed website. Available at: Updated May 21, 2013. Accessed July 19, 2013.

  • Thoracic outlet syndrome. National Institute of Neurological Disorders and Stroke website. Available at: Updated December 28, 2011. Accessed July 19, 2013.

  • Wehbe M, Leinberry C. Current trends in treatment of thoracic outlet syndrome. Hand Clin. 2004;20:119-121.