Thoracic outlet syndrome is primarily diagnosed by:

• TOS refers to compression of subclavian vessels and nerves of the brachial plexus in the region of the thoracic inlet. • Divided into: Vascular forms (Arterial and /or Venous) and Neurogenic forms • Compression resulting from TOS is dynamic and best evaluated clinically by mechanical provocative maneuvers • Symptoms most commonly develop secondary to neural compromise • Middle-aged women are most commonly affected