Thoracic outlet syndrome usually shows its symptoms as the thoracic outlet becomes constricted and compresses the nerves and blood vessels. The exact cause is not clearly defined but develops due to the following conditions:
Extra Rib Condition
In some cases, pregnant women deliver a baby with an extra rib (present above their first rib). This results in reducing the size of their thoracic outlet and compresses nerves and blood vessels.
Poor Posture and Obesity
People with deformed posture or have excess fat may have increased pressure on their joints. Due to which it causes constriction of the thoracic outlet.
Some dangerous accidents or other traumatic injuries can cause compression of the thoracic outlet as well as the vessels and nerves in this area.
Overuse of the Shoulders and Arms
Excessive use of shoulders and arms due to repetitive activities such as working at a computer or lifting heavy objects above the head can increase damage to the tissues in the thoracic outlet. The size of the thoracic outlet may shrink as time passes by, which increases pressure on the vessels and nerves.