Thoracic outlet syndrome (TOS) is a condition in which there is compression of the nerves, arteries, or veins in the passageway from the lower neck to the armpit. There are three main types: neurogenic, venous, and arterial
The neurogenic type is the most common and presents with pain, weakness, and occasionally loss of muscle at the base of the thumb
The venous type results in swelling, pain, and possibly a bluish coloration of the arm.
The arterial type results in pain, coldness, and paleness of the arm.
TOS may result from trauma, repetitive arm movements, tumors, pregnancy, or anatomical variations such as a cervical rib.
Signs and Symptoms
TOS affects mainly the upper limbs, with signs and symptoms manifesting in the shoulders, neck, arms and hands. Pain can be present on an intermittent or permanent basis. It can be sharp/stabbing, burning, or aching. TOS can involve only part of the hand (as in the pinky and adjacent half of the ring finger), all of the hand, or the inner aspect of the forearm and upper arm. Pain can also be in the side of the neck, the pectoral area below the clavicle, the armpit/axillary area, and the upper back (i.e., the trapezius and rhomboid area). Discoloration of the hands, one hand colder than the other hand, weakness of the hand and arm muscles, and tingling are commonly present.