Thoracic outlet syndrome (TOS) is a condition where nerves and/or blood vessels in the upper chest are compressed, leading to symptoms like numbness in the fingers and discomfort in the shoulder, arm, and neck. The thoracic outlet is the passageway for these nerves and blood vessels to exit the chest and supply the upper extremities.
It's bordered by muscle, bone, and other tissues. Enlargement or movement of these tissues can compress the thoracic outlet, leading to thoracic outlet syndrome. Causes include muscle enlargement (e.g., from weight lifting), injuries, an extra rib (cervical rib), weight gain, and rare tumors at the top of the lung. Sometimes, no specific cause is found.
Evolution may also contribute, as the shift from a four-legged to a two-legged posture in primates may narrow the thoracic outlet.
Types of Thoracic Outlet Syndrome
Neurogenic Thoracic Outlet Syndrome:
Can develop from trauma to the neck or chest.
Often associated with a misshapen first rib or a cervical rib, which compresses nerves.
Symptoms: Pain, numbness, tingling, headaches, or weakness in the arm and hand.
Venous Thoracic Outlet Syndrome:
Caused by compression of the subclavian vein, leading to potential blood clots.
Symptoms: Swelling, redness, coldness, or fatigue in the arm.
Overuse of the arm and shoulder can cause vein compression.
Arterial Thoracic Outlet Syndrome:
Caused by a blood clot in the subclavian artery, which carries blood from the heart to the arm.
Often linked to a cervical rib or an unusually shaped first rib.
Symptoms: Clots can form and travel down the arm toward the hand.
Symptoms
Symptoms of thoracic outlet syndrome vary based on whether nerves or blood vessels are affected:
Conditions causing encroachment of the brachial plexus space at the thoracic outlet
Frequently Asked Questions
Although many cases of thoracic outlet syndrome (TOS) cannot be prevented, the condition is treatable.
TOS may lead to greater discomfort and impaired function if left untreated. Certain types of the
condition might result in life-threatening blood clots.
Thoracic outlet syndrome can cause pain in the neck and shoulders, numbness and tingling in the fingers,
and a weak grip. If left untreated, TOS can lead to increased pain and decreased function. Certain forms
of the disease can cause serious blood clots.
The most prevalent form of TOS is neurogenic TOS, which affects mostly middle-aged women (95 percent of
persons with TOS have this version of the condition). Recent studies have shown that, in general, TOS is
more common in women than in men, particularly among those with poor muscle development, poor posture,
or both.
Thoracic outlet syndrome can cause several or all of the following symptoms: pain felt in the hand, arm,
shoulder, and/or neck, which can range from dull to sharp; weakened hand and arm that tire easily;
numbness and tingling in the shoulder, arm, and hand.
With proper treatment and management, many people with TOS can find relief from symptoms and lead normal
lives.
It's important to avoid activities that worsen symptoms, such as carrying heavy bags over the shoulder or
prolonged overhead arm movements.
Sleeping on your back with pillows supporting your neck and shoulders can help reduce pressure on the
thoracic outlet.
Yes, TOS can affect one or both arms depending on the location and severity of nerve or vessel
compression.