Thoracic outlet syndrome (SOT) is a controversial condition to this day, caused by compression of neurovascular structures in their passage between the neck and thorax. It is classified as vascular and neurogenic. If the electrophysiological tests are not positive it is subclassified as nonspecific neurogenic. This is between 95-98 % of cases, but its diagnostic criteria are not yet clear. The main aspects to be taken into account during the clinical examination are reviewed to guide the diagnosis of patients with nonspecific neurogenic SOT, such as symptoms, triggers, differential diagnosis, assessment scales and psychosocial factors.