Thoracic Outlet Syndrome (TOS) describes a constellation of symptoms that come about due to compression of the either the veins, arteries or nerves that traverse the thoracic outlet, an area where the blood vessels and nerves travel between the chest/neck and the arm. Most patients who are affected by TOS are between 20 and 50 years old with a strong female preponderance, the cause of which is unknown. The commonest type of TOS is Neurogenic (affecting the nerves) which constitutes atleast 90% of all cases. The next most common is venous TOS (affecting the subclavian vein) which occurs in up to 8% of cases followed by arterial TOS (affecting the subclavian artery) which only occurs in 2% of cases.
For more detailed information on the 3 types of thoracic outlet syndrome, click on the following links: