Thoracic Outlet Syndrome

Thoracic Outlet Syndrome

Thoracic outlet syndrome is a term used to describe the compression of nerves and / or blood vessels which travel from the neck to the armpit (axilla). Compression of these structures can cause pain, tingling, numbness and weakness from the neck and throughout the arm.

Thoracic Outlet Syndrome Symptoms

Symptoms vary depending on the exact location and structures being compressed, as well as the extent of the compression, but may include:

  • Pain in the neck or shoulder
  • Tingling or numbness in the arm
  • The arm may feel weak or easily fatigued
  • A cold hand
  • Symptoms are made worse by overhead movements

What is Thoracic Outlet Syndrome?

The thoracic outlet is the gap between the clavicle (collarbone) and the first rib. There are loads of nerves and blood vessels which run through this space, including the brachial plexus and subclavian artery and vein.

If the posture around the shoulder is not good, then the shoulder moves forwards, which lowers the collarbone. This can result in compression of the nerves and blood vessels underneath it. Similarly, tension in the scalene muscles can cause compression.

Congenital (genetic) anatomical variances can also predispose an individual to developing thoracic outlet syndrome. For example, complete cervical ribs and clavicle abnormalities. Traumatic injuries to the clavicle such as broken collarbones may also reduce the space, especially in cases of malunion.


Treatment of thoracic outlet syndrome should target correcting the cause of the compression. In most cases this is poor posture and so the following will help: