Frequently Asked Questions about Thoracic Outlet Syndrome (TOS)

What is thoracic outlet syndrome?

Thoracic outlet syndrome (TOS) is a condition that causes pain and weakness in your arm. It can also cause pain in your neck or your shoulder. This pain and weakness happen when the nerves and blood vessels that go to your arm are compressed (squeezed) because the space they need to pass through to get from your chest to your arm is too narrow.

The space that the nerves and blood vessels pass through is called the thoracic outlet. It is made up of the first rib, the collarbone, and the neck muscles.

What causes thoracic outlet syndrome?

Some people are born with a narrow thoracic outlet, or they may have been born with an extra rib that takes up more space and makes the thoracic outlet narrower.

Some people have scarring or inflammation around the thoracic outlet that makes it narrower. This scarring and inflammation could be caused by a past injury to the neck or the collarbone, or it could be from doing repetitive arm motions over a long period of time. Many of the people who have TOS are athletes, construction workers, computer programmers, and others who spend a lot of time doing the same arm motions over and over again.

What are the symptoms of thoracic outlet syndrome?

The symptoms depend on what is being compressed. In the majority of cases, the nerve is being compressed. This makes your arm feel weak when you lift things, or it can cause a pain that shoots down your arm. That pain often feels worse if you raise the arm or carry something heavy.

If the vein is being compressed, that can cause swelling in your arm and hand. The swelling usually gets worse over the course of the day. You may find that elevating your arm on a pillow reduces the swelling, but it returns the next day.

In more severe cases, the vein is so compressed that the blood stops flowing properly, and that can cause the blood in the vein to clot. A clot requires urgent medical care.

In rare cases, the artery that supplies blood to the arm is compressed. This can cause pain and a feeling of coldness in your hand. Sometimes this can cause severe sores on your fingers.

Does everyone with thoracic outlet syndrome require surgery?

For most people who have TOS, the symptoms are not severe enough to require surgery. Instead, they can do physical therapy exercises that help to make the thoracic outlet wider, which can reduce the symptoms. Changes in lifestyle can also help. These changes may include improving posture, losing weight, and avoiding the repetitive motions or other activities that cause the symptoms.

If the symptoms are too severe for physical therapy, or if the blood vessels are too compressed, your doctor may decide that surgery is a better option.

Can thoracic outlet syndrome improve on its own?

No. For people who have mild TOS, lifestyle changes may be enough to make the symptoms go away. But more serious TOS should be treated by a doctor as soon as possible.

If you have TOS and wait too long to get it treated, you may have serious complications. When the nerve compression is severe, your arm could become very weak or even disabled. If the blood vessels are severely compressed for a long time, the blood in the vessels can clot and prevent your arm from getting enough blood circulation.

What happens during thoracic outlet syndrome surgery?

Every TOS patient’s surgery depends on the patient’s individual conditions. In most cases, removing some of the neck muscles and the first rib can create enough space for the nerves and blood vessels to pass through. Sometimes the surgeon may need to remove other structures to create enough space.

When the artery or blood vessels are involved, you may also need to have the blood vessels repaired after the compression is removed.

What are possible complications of thoracic outlet surgery?

TOS is a relatively low-risk procedure when done by a surgeon who has the right expertise. Your surgeon should have advanced knowledge of neck anatomy to avoid injuring nerves and blood vessels.

Because the lung is close to the thoracic outlet, sometimes the surgery will cause air to be trapped between the lung and the chest wall. This requires a chest tube to drain the air out.

Other less common complications include bleeding, injury to lymphatic channels, and infection.

How long will it take me to recover after surgery?

The usual hospital stay after TOS surgery is two days. After leaving the hospital, patients can return to their normal daily routine but should not lift anything heavier than 10 pounds for four weeks.

Some patients may have some occasional discomfort, but the pain from the surgery can be controlled with over-the-counter pain pills.

Last reviewed: 
April 2019

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