Are You Feeling Numbness or Pain Down Your Arm? It Might Be Thoracic Outlet Syndrome

Do you sometimes feel a strange pain or numbness starting in your neck or shoulder and traveling all the way down your arm? You might notice this pain gets worse when you try to lift heavy objects or reach your hands up high. If you have these signs, the cause might be a condition with a long medical name. Today we are talking about Thoracic Outlet Syndrome, often called TOS.

The name can sound a bit scary at first. However, once you learn more about it, you can understand what is happening in your body and find ways to feel better. Let us walk through what TOS means, why it happens, and how you can get the help you need.

What Is Thoracic Outlet Syndrome?

Simply put, Thoracic Outlet Syndrome (TOS) is a group of health signs that happen when the nerves or blood vessels in your lower neck and upper chest are squeezed. Doctors call this narrow space between your neck and chest the thoracic outlet.

Think of this space as a doorway between your neck and chest. Important nerves, the artery that carries clean blood to your arm, and the veins that bring used blood back to your heart all pass through this doorway. The most important structures here are a bundle of nerves called the brachial plexus, the subclavian artery, and the subclavian vein.

Normally, this thoracic outlet is large enough for these nerves and blood vessels to move freely without any trouble. However, sometimes changes in your body from birth, or injuries to your neck and chest, make this space smaller. When the space gets narrow, nearby bones or muscles start to squeeze the nerves or blood vessels.

This squeezing causes pain, numbness, and other signs in your arm, shoulder, and neck. Because these signs can look like many different problems, finding out that you have TOS can sometimes take a little time. Fortunately, you do not need to worry too much because many people find relief with simple treatments like physical therapy and pain medicine. If those treatments do not work, or if blood flow has a serious block, a doctor might suggest surgery.

Are There Different Types of TOS?

Yes, doctors divide TOS into three main types based on what is being squeezed:

Neurogenic TOS

This is the most common type of TOS. About 95 percent of all TOS patients belong to this group. Here, the brachial plexus—the network of nerves traveling from your neck through your armpit and down your arm—gets compressed. This often happens in people who are in their 30s. Repetitive stress injuries from doing the same motion over and over, especially in sports, and neck injuries like whiplash from car accidents are major causes.

Venous TOS

In this type, your subclavian vein gets squeezed. This is the main blood vessel that carries used blood back from your arm to your heart. This type happens a bit more often in males, usually between the ages of 20 and 30. Symptoms usually show up in your dominant arm.

Arterial TOS

This is the rarest type of TOS. Only about 1 percent of all TOS patients have this kind. However, arterial TOS is a major reason why blood clots suddenly form in the arms of people under 40. Here, your subclavian artery—the main blood vessel carrying oxygen-rich blood from your heart to your arm—gets squeezed. This is often caused by an extra rib you are born with, called a cervical rib. Since about 70 percent of people with a cervical rib are women, this type of TOS is more common in women.

Doctors sometimes group venous and arterial TOS together and call them Vascular Thoracic Outlet Syndrome. These two types usually need surgery to reduce symptoms and prevent dangerous complications. Neurogenic TOS usually responds well to physical therapy and exercises, though some people may still need surgery.

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How Common Is This Condition?

Researchers estimate that each year:

• Neurogenic TOS affects about 1 person out of every 40,000 people.
• Venous TOS affects about 1 person out of every 125,000 people.

Because this condition can be hard to diagnose correctly, the actual number of people living with this illness might be much higher.

What Are the Signs of TOS?

TOS signs usually show up on one side of your upper body, such as your neck, upper chest, shoulder, arm, or fingers. You might notice:

• Pain: This pain can get worse when you raise your arm.
• Numbness or a pins-and-needles feeling.
• Loss of feeling or a dead arm sensation.
• Weakness in your arm and hand.
• Swelling or a heavy feeling in your arm.
• Changes in your skin color, such as pale or bluish skin.
• A cold feeling when you touch your skin.
• Slower healing of cuts or sores on your fingers.

Your signs can change depending on which type of TOS you have, because the signs depend on what is being squeezed:

• Your brachial plexus gives your arm movement and feeling. When this nerve network gets squeezed, you feel pain and numbness.
• Your subclavian vein carries blood away from your arm. When this vein gets squeezed, blood cannot drain properly, causing your arm to swell and feel heavy.
• Your subclavian artery supplies your arm with oxygen-rich blood. When this artery gets squeezed, blood flow to your arm and fingers drops, causing weakness, numbness, pain, and cold skin.

How Does TOS Pain Feel? Does It Confuse With Angina?

TOS can make your neck, upper chest, shoulder, and arm ache. This can feel like a dull, nagging pain that gets worse when you move your arm around.

Some people confuse TOS pain with a heart condition called angina. Angina is chest pain that happens when your heart muscle does not get enough oxygen. However, these two conditions have important differences:

• TOS pain does not start or get worse when you walk around, but angina pain often does. Angina can also come with trouble breathing, a fast heartbeat, or dizziness.
• TOS pain usually gets worse when you raise the painful arm. Angina does not do this.

Important: Do Not Confuse TOS With a Heart Attack or Stroke

This is something you must remember clearly. Some signs of TOS can look like serious emergencies such as a heart attack or a stroke. For example:

• Chest pain, especially if it starts suddenly and unexpectedly, can be a sign of a heart attack. However, a heart attack often brings extra signs like trouble breathing, stomach pain, sweating, or a feeling of sudden doom.
• Weakness on one side of your body can be a sign of a stroke. However, a stroke also brings other signs, such as slurred speech, a drooping face on one or both sides, or sudden vision loss.

What Causes TOS?

Doctors divide the causes of TOS into three main groups:

Congenital Causes

These are physical traits you are born with. For example, you might be born with an extra rib in your neck, called a cervical rib. This extra rib sits close to your first rib and sometimes connects to it. You might also have unusual traits in your ribs, neck muscles, or nearby ligaments. These variations make the thoracic outlet narrow and squeeze your nerves or blood vessels.

Traumatic Causes

These are sudden injuries to your neck and upper chest. Car accidents, especially injuries that cause whiplash, are common examples. Imagine riding in a vehicle and having your neck snap back and forth in a sudden crash. That kind of injury can easily trigger this condition.

Functional Causes

These happen when repetitive activities wear down the structures inside your thoracic outlet. Athletes—especially cricket players, pitchers, batters, and swimmers—often get TOS from moving their arms quickly over and over. Certain jobs that require you to lift objects above your head all day can also cause it. Even sitting at a computer all day with poor posture puts you at risk.

Some people are born with factors that make them prone to TOS, but they will not feel any signs until they experience a neck injury or damage the area by repeating the same motions for a long time.

Who Is Most at Risk for TOS?

You might have a higher risk of developing TOS if you:

• Play sports that require repetitive arm or shoulder movements, such as cricket, swimming, golf, or volleyball.
• Do heavy weightlifting exercises.
• Carry heavy bags on one shoulder or lift items over your head often, such as construction workers or warehouse workers.
• Have a past injury to your neck or spine, such as whiplash.
• Have tumors or large lymph nodes in your upper chest or armpit.
• Have poor posture when sitting or standing, like hunching over a computer all day.

Is TOS Serious? What Are the Possible Complications?

If you leave Thoracic Outlet Syndrome untreated, it can lead to serious complications. Some of these include:

• Blood clots in your armpit and nearby veins, known as axillo-subclavian vein thrombosis.
• Ongoing swelling and pain in your arm, especially in people with venous TOS.
• Tissue death, known as gangrene.
• Non-healing skin sores on your fingers, known as ischemic ulcers, caused by poor blood flow.
• Permanent nerve damage.
• A blood clot traveling to your lungs, known as a pulmonary embolism, which is a very dangerous emergency.

As you can see, you should never brush this off as a simple arm ache. Finding the condition early and getting treatment is very important.

How Do Doctors Diagnose TOS?

A doctor will examine you, ask about your medical history, and decide if you have TOS. During a physical exam, your doctor may ask you to perform certain movement tests, such as:

• Upper limb tension tests to check if your upper arm experiences stress.
• Elevated arm stress tests, where you hold your arms up.

During these tests, your doctor will ask you to lift your arms, turn your head, or make a fist. The doctor watches to see which movements bring on your pain or other signs. These results help point toward the right diagnosis.

To confirm TOS and rule out other causes for your signs, your doctor may also order lab tests and imaging tests.

What Other Tests Are Done?

You might need one or more of these tests:

• Blood tests.
• A chest X-ray.
• A computed tomography (CT) scan of your chest and spine.
• An electromyography (EMG) test to check how well your muscles and nerves work.
• A magnetic resonance angiography (MRA) of your blood vessels.
• A magnetic resonance imaging (MRI) scan of your chest and spine.
• A nerve conduction study to measure how fast signals travel through your nerves.

These tests help your doctor:

• Check for birth variations, such as a cervical rib.
• See how blood flows through your arteries and veins.
• Rule out other health issues that cause similar signs.
• Check how your muscles and nerves are functioning.
• Find the exact spot where the squeezing is happening.

What Treatments Are Available for TOS?

Treatments for TOS depend on the type you have and your specific signs. The main goals of treatment are to reduce your signs and prevent complications. Your doctor will choose the treatment plan that fits you best.

Some common treatment choices include:

• Physical therapy: This is the main starting treatment for neurogenic TOS. A physical therapist will help you increase your neck and shoulder range of motion, strengthen your muscles, and teach you how to keep good posture. Many people with neurogenic TOS find great relief with this approach.
• Pain medicine: Your doctor may suggest over-the-counter pain medicines, such as NSAIDs (nonsteroidal anti-inflammatory drugs).
• Blood-thinning or clot-dissolving medicines: People with arterial or venous TOS can benefit from thrombolytic therapy. This treatment uses an intravenous (IV) line or a catheter to deliver medicine that dissolves existing blood clots and stops new ones from forming. Your doctor may also prescribe anticoagulant medicine to prevent blood clots.
• Surgery: Many people with arterial or venous TOS need surgery. Some people with neurogenic TOS also need surgery if other treatments do not help. Surgeons use different operations depending on your TOS type and your body. For example, a decompression surgery removes an unusual bone or tissue that causes the squeezing. Other surgeries fix structural problems in blood vessels to restore good blood flow. Your doctor will explain whether you need surgery, how it works, and what risks are involved.

Will TOS Go Away on Its Own?

No, do not wait for your signs to go away on their own. If you have signs of TOS, seek medical advice right away. While simple steps like physical therapy help many people, some people need surgery or other medical treatments to prevent serious complications. Your doctor will tell you what treatment plan fits your needs.

Can You Prevent TOS?

You cannot always prevent TOS because many causes are out of your control, such as how your body is built from birth. However, you can take steps to lower your risk:

• If you play a sport with repetitive arm movements, talk to your coach or trainer about exercises that strengthen the muscles around your shoulders.
• If your job requires heavy lifting or working with your arms raised high, talk to a doctor about exercises that help lower your risk of injury.
• Maintain good posture. Keep your spine straight when you sit, stand, and work.
• Avoid staying in one position for too long. Stand up, walk around, and stretch your body at least once every hour.

What to Expect and How to Care for Yourself

Your outlook if you have TOS depends on which type you have. Your doctor is the best person to give you a clear picture of what to expect.

If you have TOS, follow your doctor's advice on how to care for yourself. Your doctor may tell you to:

• Cut back on or stop carrying heavy shoulder bags and lifting items over your head.
• Work with a physical therapist and do the exercises they give you.
• Do home exercises to build muscle strength and improve your posture.
• Change your daily activities to limit or avoid movements that make your signs worse.

When to See a Doctor and Questions to Ask

If you develop new signs, or if your current signs change, talk to your doctor. Your doctor will tell you how often you need checkups and tests.

If you were recently diagnosed with Thoracic Outlet Syndrome, here are some questions you can ask your doctor:

• What type of Thoracic Outlet Syndrome do I have?
• What is causing this condition in my body?
• What treatments do you recommend, and how long will they take?
• How will we know if the treatment is working?
• What risks come with these treatments?
• What changes should I make to my daily routines or habits?
• What can I do at home to help reduce my signs?
• What is my long-term outlook?

If you have any questions about your condition, treatment plan, or outlook, be sure to talk to your doctor.