If you have hand or arm pain (or numbness) you might have thoracic outlet syndrome. It affects up to 2 percent of the population, but most people have never heard of it. In fact, this condition initially goes completely undiagnosed in almost all cases. That’s because it mimics many other dysfunctions, fooling even the trained medical eye. So it’s important to know what to look for in order to get the proper treatment.

Thoracic Outlet Syndrome is a Wonderful Imposter

There are many pathologies of the human body that can mimic another condition. This is one reason doctors must be careful when diagnosing an abnormality. Why is that important?

First, these imposter conditions may result in improper treatments. Imagine having surgery unnecessarily because of a wrong diagnosis! This is a real-world problem surgeons must deal with every day.

A proper diagnosis will also enable doctors to address the problem directly. If it's not addressed, the abnormality will go untreated, and possibly worsen. Therefore, you and your doctor can avoid improper treatments and find a speedy remedy by ensuring the diagnosis is correct to begin with.

Without a proper diagnosis, many people with thoracic outlet syndrome incorrectly attribute its symptoms to something else. Actually, it’s most common for sufferers to believe they have either carpal tunnel syndrome or tendonitis. These are completely unrelated conditions that share similar symptoms.

But in reality, there are a number of pathologies often confused with thoracic outlet syndrome. The table below lists the more obvious ones, along with their distinguishing features.

What is thoracic outlet syndrome?

Thoracic outlet syndrome is actually a group of related disorders. They occur due to a common problem in one specific area of the body. That area is the space between the first rib and the collarbone. This space is the “thoracic outlet" and various blood vessels and nerves run through it.

Problems occur in some people when this space constricts. It results in crushing either the blood vessels or nerves that pass through. The crushing action ultimately results in symptoms like numbness in the fingers and pain in the shoulders or neck.

Thoracic outlet syndrome can be one of three primary types:

• Neurogenic 
• Venous 
• Arterial 

Venous and arterial thoracic outlet syndromes are rarer than the neurogenic type. They involve compression of either an artery or vein in the thoracic outlet space. 

However, approximately 90% of all thoracic outlet syndromes are of the neurogenic type. Therefore, neourgenic throacic outlet syndrome is the focus of the present discussion.

Causes

Neurogenic thoracic outlet syndrome occurs from the compression of the spinal nerve roots. These roots arise from C5 to T1. They form the "brachial plexus".

The most common cause of thoracic outlet syndrome is trauma from motor vehicle accidents. However, many people who have repetitive strain injuries are prone to getting thoracic outlet syndrome. 

These repetitive strain injuries can be work-related or may occur with sports activities. The most often cited sports activities that result in thoracic outlet syndrome are bodybuilding, baseball, volleyball, golf, and swimming.

A smaller percentage of people with this condition have defects in their anatomy. For instance, having an extra cervical rib can produce the condition. The extra rib crowds the already tight thoracic outlet space, compressing adjacent tissues. 

Pregnancy is another cause of thoracic outlet syndrome. However, doctors rarely test for it because symptoms normally disappear after childbirth. 

Still fewer people develop thoracic outlet syndrome if they have sleep disorders, tumors or large lymphatic nodes in the upper chest (including the armpit). But in a large majority of cases, the cause of the condition is completely unknown.

Symptoms

Thoracic outlet syndrome occurs in 1 out of 50-100 people. Nearly half of them have pain in the upper limbs. Other frequently reported symptoms include tingling and numbness in the arm and hand. Less frequent symptoms include arm, hand or finger soreness, coldness, itching and weakness. Women are three times more likely to have it. 

Most people with neurogenic thoracic outlet syndrome have upper extremity issues almost exclusively. Usually the complaints are mild and tolerable. Patients normally can ease symptoms just by changing the position of their limb. 

Symptoms of neurogenic thoracic outlet syndrome can occur in one or both hands and arms. They can also involve different areas of the upper body. For example, the right hand may tingle while the left shoulder hurts. However, most patients have symptoms in only one upper extremity.

While symptoms vary widely from patient to patient, certain patterns occur. Most patients with neurogenic thoracic outlet syndrome will probably have at least two of the following:

• Pain, tingling or numbness in the shoulder, arm, fingers or hand
• Perception of hand or arm weakness (especially with the arm elevated)
• Pain or tension in the neck or upper back 
• Headaches in the rear of the head
• Symptoms worsen while lying on the back, face-up
• Cold feelings, swelling or sporadic discoloration in the hands and fingers

Typically, patients with neurogenic thoracic outlet syndrome describe worsening symptoms when they elevate their arm. They can trigger symptoms by:

• Reaching for high objects
• Lifting with an outstretched arm
• Catching or throwing
• Long hours of typing on computers
• Gripping a steering wheel
• Holding a phone to the ear
• Brushing, drying or combing hair

A note about muscle weakness: Patients may perceive pain in the affected limb as muscle weakness. But actual muscle weakness and atrophy (muscle degeneration) is rare with thoracic outlet syndrome. Therefore, it’s important to distinguish between perceived muscle weakness and actual muscle atrophy in order to rule out another neuromuscular condition.

Treatments for thoracic outlet syndrome

There are several ways to manage thoracic outlet syndrome. By far, the most successful is physical therapy. Its goal is to optimize posture, alignment, and movement patterns. Specifically, the therapist will attempt to:

• Relieve muscle spasms
• Improve limb mobility
• Strengthen muscles
• Advise on how to eliminate repetitive strain on the job
• Improve any problems with seated or standing posture

Physical therapy treatment typically lasts for 4-6 weeks. Depending on the severity, therapy is required at least every other day during this time period. Significant improvement of symptoms often results.

Doctors often prescribe drugs to manage neurogenic thoracic outlet syndrome. The more common drugs are:

• Nonsteroidal anti-inflammatory agents (NSAIDs) like Advil, Tylenol, Aleve
• Muscle relaxers
• Analgesics

Note that the FDA Cautions against taking some common pain relievers chronically. That's because serious liver damage may result. 

Local botulinum toxin injections for thoracic outlet syndrome can also be used. They can reduce spasm in the muscles responsible for brachial plexus nerve root compression. But this therapy is uncommon.

Even less common is surgery for thoracic outlet syndrome. Surgery aims to remove or reduce any tissue compressing the nerve root. The tissue targeted can be muscle, the first rib or fibrous scarring. However, only patients with extensive disability (and who failed with other measures) are surgical candidates.

Tests thoracic outlet syndrome

Most doctors will diagnose thoracic outlet syndrome if 3 of the 5 tests below are positive. You can perform these tests at home. But results will vary depending on your commitment to performing the tests properly. 

First, select a willing assistant to help you. Then find a quiet room for about 40 minutes. Perform each test several times to ensure you properly execute each one. Make a determination only when your results are repeatable.

1. Elevated Arm Stress Test

Raise both arms. Keep elbows slightly behind your head. Open and close your hands slowly (every few seconds) for 3 minutes. A positive sign will be heaviness, pain or arm weakness. You may also feel hand or finger numbness or tingling. 

2. Adson or Scalene Maneuver

Your assistant finds your radial pulse (the pulse below the wrist crease, on the thumb side). Then rotate your head toward the tested arm. Let your head tilt backward to stretch your neck. The assistant extends your arm, slightly backward. A positive sign is if the radial pulse disappears.

3. Costoclavicular Maneuver 

The assistant locates your radial pulse again. Then the assistant draws your shoulder down and back as you lift your chest in an exaggerated "at attention" posture. A positive sign is an absence of the radial pulse. 

4. Allen Test

The assistant locates your radial pulse once again. The assistant flexes your elbow 90 degrees while your upper arm extends horizontally and rotates laterally (backward). Then turn your head away from the tested arm. It’s a positive sign if the radial pulse disappears as your head rotates. 

5. Provocative Elevation Test 

Doctors use this test on patients who already have obvious symptoms. But it's a very useful, confirmatory test. As you sit, the assistant grasps both elbows. You remain passive as the assistant elevates both shoulders forward, and finally into full elevation. Hold this position for 30 seconds.

You and the assistant should watch for increased heart rate, skin color change (pinker), and increased hand temperature. But these can happen in normal individuals. However, a positive sign is also having feelings of numbness, pins and needles or tingling in your arms or hands. You may even feel some pain. Most patients say a positive sign is similar to feeling an arm "falling asleep" and then circulation returns.