The narrow space between your collarbone and first rib is known as the thoracic outlet. Blood vessels, nerves, and muscles that extend from the back to the arms pass through this area. If the space in the thoracic outlet is too narrow, these structures may become compressed. Pressure on blood vessels and nerves may result in pain in your shoulders. It may also cause numbness or tingling in your hands. This condition is known as thoracic outlet syndrome.
Symptoms of thoracic outlet syndrome occur when the space between your collarbone and first rib becomes too small. This can occur because of a number of different conditions including:
Having an Extra Rib
Some people are born with an extra rib above their first rib. This reduces the size of their thoracic outlet and compresses nerves and blood vessels.
Poor Posture and Obesity
People who do not stand up straight or have excess abdominal fat may have increased pressure on their joints. This can cause a narrowing of the thoracic outlet.
Car accidents and other traumatic injuries can compress the thoracic outlet and the vessels and nerves in this area.
Overuse of the Shoulders and Arms
Repetitive activities such as working at a computer or lifting objects above your head can result in damage to the tissues in the thoracic outlet. Over time the size of the thoracic outlet may shrink, placing pressure on your vessels and nerves.
The symptoms that you experience as a result of thoracic outlet syndrome will depend on the specific nerves or blood vessels that are compressed. If your nerves are compressed this can result in:
- pain in various areas of the neck, shoulder, arm, or hand
- numbness in the forearm and fingers
- weakness of the hand
If your blood vessels are compressed this can result in:
- swelling of the arm
- redness of the arm
- hands or arms that feel cold to the touch
- hands and arms that become easily fatigued
In addition to these symptoms you may find it difficult to lift objects above your head. The range of motion in your shoulders and arms may also be limited.
Your doctor will give you a physical exam and take your health history to determine if you have risk factors for thoracic outlet syndrome.
During your exam, your doctor may use provocation tests. These tests reproduce your symptoms and can help your doctor diagnose the condition. One provocation test requires you to put your hands over your head and to open and close your hands for three minutes. If your symptoms develop during this test, it typically confirms that you have thoracic outlet syndrome.
To confirm your diagnosis, your doctor may also order additional tests including:
- X-ray of the thoracic outlet
- electromyography, which allows your doctor to see how muscles and nerves in the thoracic outlet are working
- nerve conduction study
Treatment for thoracic outlet syndrome typically focuses on lifestyle changes and medications to help reduce your symptoms. Physical therapy is often recommended to help strengthen shoulder muscles. Strengthening these muscles will improve support for the collarbone. If you are overweight, your doctor may recommend a weight-loss program. Over-the-counter medications such as naproxen or ibuprofen may also be used to reduce inflammation and pain.
If nonsurgical treatment is not effective in relieving your symptoms, your doctor may recommend surgery. Surgery for this condition would involve your doctor removing your extra rib (if you have one), removing a section of your first rib, or rerouting blood vessels around the area. If the vessels in your thoracic outlet are narrowed, angioplasty may be used to open them up.
In many cases, nonsurgical treatment of thoracic outlet syndrome will alleviate symptoms. If surgery is required, it can be effective. However, some individuals will experience a recurrence of their symptoms after surgery.
It may not be possible to prevent thoracic outlet syndrome. If the condition develops, you can take steps to reduce symptoms and to prevent it from recurring. If you have the condition, you should not carry heavy bags on your shoulders. Doing so may push the collarbone down and increase pressure on vessels in the thoracic outlet. If you have symptoms of the condition, you should also do strengthening exercises to prevent the recurrence of the condition.