Thoracic Outlet Syndrome
What is it?
Thoracic outlet syndrome (TOS) is a group of disorders characterized by pain, numbness and weakness in the neck, shoulders, arms or hands. Symptoms arise from compression of or direct injury to nerves or blood vessels in the thoracic outlet.
The thoracic outlet is the space located between the collar bone and uppermost rib on either side of your body. Many arteries, veins, muscles and nerves that serve your arm pass through this space. Narrowing of this space can put pressure on these nerves or blood vessels and interfere with their normal function. Learn more.
Various conditions, including injury, weight gain, poor posture and congenital abnormalities, can alter the size and shape of this space. But often, no specific cause for compression of the thoracic outlet can be found.
Types of TOS
There are 3 main types of TOS, based on which vessels or nerves are affected:
Fortunately, you can take steps to help you feel better and manage your symptoms. You may benefit from one or a combination of treatments, including physical therapy, medication, and cognitive behavioral therapy. Your health care provider can help you design a treatment plan that works for you.
Nerve and blood vessel function
To do their job, nerves and blood vessels need adequate space. If they are squeezed or compressed, they may not function well. Compression of blood vessels at the thoracic outlet can impair blood flow to and from the arm and hand. It also can cause blood clots to form, which may further slow or completely block blood flow through the affected vessel. If clots break lose, they may move down the arm, plugging smaller blood vessels in the arm or hand. Sometimes, a clot travels to the lungs – a life threatening condition called pulmonary embolism. Nerves also need room to stretch or lengthen when the arm moves. If a nerve in the thoracic outlet is compressed or cannot move freely, you may not be able to move your arm normally. Pain and altered sensation in the arm also can occur.
Anyone can get TOS but certain factors may increase the risk:
The thoracic outlet is the space located between the collar bone and uppermost rib on either side of your body. Many arteries, veins, muscles and nerves that serve your arm pass through this space. Narrowing of this space can put pressure on these nerves or blood vessels and interfere with their normal function. Learn more.
Various conditions, including injury, weight gain, poor posture and congenital abnormalities, can alter the size and shape of this space. But often, no specific cause for compression of the thoracic outlet can be found.
Types of TOS
There are 3 main types of TOS, based on which vessels or nerves are affected:
- Neurogenic TOS involves compression of the brachial plexus. This is the most common type of TOS, accounting for the vast majority of cases.
- Venous TOS involves compression of the subclavian vein. It is a less common form, affecting less than 4% of people with TOS.
- Arterial TOS involves compression of the subclavian artery – is the rarest type of TOS.
Fortunately, you can take steps to help you feel better and manage your symptoms. You may benefit from one or a combination of treatments, including physical therapy, medication, and cognitive behavioral therapy. Your health care provider can help you design a treatment plan that works for you.
Nerve and blood vessel function
To do their job, nerves and blood vessels need adequate space. If they are squeezed or compressed, they may not function well. Compression of blood vessels at the thoracic outlet can impair blood flow to and from the arm and hand. It also can cause blood clots to form, which may further slow or completely block blood flow through the affected vessel. If clots break lose, they may move down the arm, plugging smaller blood vessels in the arm or hand. Sometimes, a clot travels to the lungs – a life threatening condition called pulmonary embolism. Nerves also need room to stretch or lengthen when the arm moves. If a nerve in the thoracic outlet is compressed or cannot move freely, you may not be able to move your arm normally. Pain and altered sensation in the arm also can occur.
Who Gets TOS?
Anyone can get TOS but certain factors may increase the risk:
- Gender – Women are diagnosed with TOS more often than men.
- Age – TOS typically develops between ages 20 and 50.
- Medical conditions – TOS often is associated with another medical condition such as rotator cuff tendonitis, cervical arthritis, brachial plexus injury, hypothyroidism or diabetes.