What Is Thoracic Outlet Syndrome?

Thoracic outlet syndrome is a set of symptoms affecting the shoulder, arm or hand due to pressure on the nerves and blood vessels in the upper part of the chest.

The “thoracic outlet” is the name of space between the collarbone and first rib. It can become damaged or narrowed because of an accident, pregnancy or a congenital (present at birth) defect. This creates abnormal pressure or irritation of the nerves and blood vessels that pass through this area, causing pain and numbness down the limb.

There are three main types of thoracic outlet syndrome:

  • Neurogenic: This type affects the brachial plexus, a network of nerves that originates in the spinal column and controls the arm.
  • Vascular: This type affects the veins and arteries under the collarbone, especially the subclavian vein and subclavian artery.
  • Nonspecific: This describes a chronic pain that has no known cause.

The majority of thoracic outlet syndrome cases are neurogenic.

Thoracic outlet syndrome can happen to anyone at any age, but it is most common in women, young adults and athletes who participate in sports that require repetitive motion of the arm and shoulder, such as swimming, baseball and volleyball.