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Thoracic Outlet Disorders

Thoracic Outlet Syndrome describes a group of disorders that occur when blood vessels or nerves in the space between your collarbone and first rib are compressed in the already crowded space at the thoracic outlet. In most cases, symptoms are neurological with pain and weakness as a result of nerve root compression. 

There are three main types of thoracic outlet syndrome depending on the location of compression in the primary structure.  These may occur separately or together;

  1. Arterial TOS (subclavian artery)
  2. Venous TOS (subclavian vein)
  3. Neurogenic (neurological) TOS (brachial plexus nerve roots)

Thoracic outlet syndromes affected the blood vessels are less common. These would give rise to symptoms such as thrombosis (clot) of the subclavian vein and aneurysms (ballooning) of the subclavian artery.

What are the causes of Thoracic Outlet Syndrome?

Often TOS is initiated by a physical trauma eg. a car accident, repetitive injuries from job or sports related activities, poor posture, certain anatomical variations and sometimes pregnancy can also cause thoracic outlet syndrome.  Symptoms can vary depending on which structures are compressed. 

Arterial and Venous TOS occurs when one or more of the veins or arteries under the collarbone are compressed.  Symptoms can include discoloration of your hand, arm pit pain and swelling, blood clots in veins or arteries in the upper body, cold fingers/hands/arm, arm fatigue with activity, numbness or tingling in your fingers, weakness of arm or neck or a throbbing lump near your collarbone.

When nerves (neurogenic/neurological TOS) are compressed, signs of neurogenic TOS is characterised by compression of the brachial plexus. This is a complex network of nerves that arise from your spinal cord and control movement and sensation in your shoulder, arm and hand. Symptoms can include muscle wasting in the fleshy base of your thumb, numbness or tingling in your arm or fingers, pain or aches in your neck, shoulder or hand and weakening grip.


Early diagnosis of Thoracic Outlet Syndrome is important to prevent progressive nerve damage.  In most instances, symptoms resolve with physiotherapy and pain relief.  In some instances, surgical intervention may be required.  Dr Velu specialises in the detailed and careful treatment of venous and arterial thoracic outlet syndrome for your needs.