Thoracic Outlet Syndrome



TOS may be due to:

  • Defects in nearby structures
  • Trauma
  • Poor posture

Risk Factors

Things that raise the risk of TOS are:

  • An extra rib or a first rib that is not typical
  • Trauma
  • Motions that a person repeats 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 one or both arms turning pale and blue


The doctor will ask about symptoms and past health. A physical exam will be done.

The doctor will ask the person to hold their arms and head in positions that may cause TOS. The results of these tests will help show if they have TOS.

The person may also have:

  • Blood tests
  • Electromyography and other tests of the nerves

Pictures may be taken with:



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


The person may need to take:

  • Nonsteroidal anti-inflammatory drugs (NSAIDs)
  • Muscle relaxants
  • Antidepressants
  • Blood thinners
  • Anti-platelet medicines

Physical Therapy

A therapist will make an exercise plan. It will help to ease symptoms by relaxing nearby muscles. This will help improve posture better and ease pressure on nerves and blood vessels.

Lifestyle Changes

The person may need to:

  • Avoid activity that causes pain.
  • Practice good posture.
  • Avoid repetitive motion.
  • Change your workstation layout.
  • Exercise regularly.


If other treatments fail, the 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 cannot be prevented.

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.

Edits to original content made by Denver Health.