Thoracic outlet syndrome (TOS) is a condition that involves compression of the neurovascular structures that pass through the thoracic outlet, which is the space between the collarbone and the first rib. This compression can lead to symptoms such as pain, numbness, and weakness in the upper extremities. There are three types of TOS: neurogenic TOS, vascular TOS, and non-specific TOS. Diagnosis of TOS can be challenging due to the variety of symptoms it presents, and treatment options often include physical therapy, medications, and in severe cases, surgery. Research in this area focuses on improving diagnostic criteria and treatment options for individuals with TOS.