Thoracic outlet syndrome (TOS) is a multifaceted condition that arises from the compression of spinal nerves and blood vessels within the thoracic outlet (the region between the neck and shoulder). Although TOS is estimated to occur in 1 to 2 percent of patients, the disease can frequently go undiagnosed because its constellation of symptoms will frequently mimic common neck and shoulder problems.
Literature indicates that between 70% and 90% of cases are classified as neurogenic. This means that nerve diseases are primarily responsible for TOS occurrences. Thoracic outlet syndrome is most prevalent among females between the ages of 20 to 50 years, athletes, and individuals who maintain poor posture or who engage in repetitive activities with their upper extremities.
What is Thoracic Outlet Syndrome?
Thoracic Outlet Syndrome (TOS) is a medical condition resulting from compression of blood vessels or nerves in the thoracic outlet (the narrow space between your first rib and clavicle).
The thoracic outlet serves as a pass-through for important structures of our bodies, including veins, arteries, and nerves that supply blood and sensation to our arms/hands.
When the thoracic outlet becomes narrowed due to one or more of the following conditions - poor posture, repetitive strain injuries, anatomical abnormalities (extra ribs), or tight muscles/ligaments - the structures inside become compressed or pinched, resulting in symptoms of neck/shoulder pain, numbness/tingling in the arms, weakness, swelling, and/or color changes.
The three types of thoracic outlet syndrome are:
- 1. Neurogenic Thoracic Outlet Syndrome (TOS): It is the most commonly diagnosed form of TOS and affects the nerves.
- 2. Venous Thoracic Outlet Syndrome: It affects veins and may cause swelling or discoloration of an arm; and
- 3. Arterial Thoracic Outlet Syndrome: It is the rarest form of Thoracic Outlet Syndrome, affecting arteries and resulting in reduced blood flow to the arm.
While most cases of TOS are not life-threatening, they can have a profound effect on everyday life if not treated. If TOS is recognized and treated early, it will reduce symptoms and avoid long-term complications.
Symptoms of Thoracic Outlet Syndrome
Thoracic Outlet Syndrome (TOS) can manifest itself in different ways. Depending on where the compression occurs determines what type you have. Symptoms of TOS may develop slowly over time and worsen increasingly when elevating your arms or participating in repeated overhead activities.
Symptoms of TOS include:
- Neck, shoulder, upper back, or arm pain;
- Arm, hand, or fingertip numbness/tingling;
- Arm weakness/fatigue or weak grip;
- Symptoms worsen with prolonged sitting and/or poor posture
Neurogenic TOS Symptom:
- Tingling/pins and needles sensation in fingers;
- Weak hand grip strength/clumsy hands;
- Pain that radiates from the neck into the arm;
- Muscle wasting at the base of the thumb, if severe.
Venous TOS Symptoms:
- Swelling in your arm or hand;
- Blue/purple discoloration in your skin;
- Heaviness/tightness in your arm;
- Prominent, bulging veins on your shoulder/chest.
Arterial TOS (rarest form of TOS) Symptoms:
- Cold/pale hand/fingers;
- Lack of or very weak pulse in your arm;
- Pain in your arm while active.
- Delayed healing of wounds or skin ulcer (if severe).
Due to the similarities in the symptoms of TOS and other conditions, it is frequently misdiagnosed, and anyone with ongoing or worsening symptoms should see a medical professional for evaluation and to receive the proper diagnosis and treatment as soon as possible.
Risk Factors for Thoracic Outlet Syndrome
Several risk factors contribute to the likelihood of developing Thoracic Outlet Syndrome (TOS), especially those that lead to prolonged pressure applied to the nerves or blood vessels contained within the thoracic outlet.
Age and sex of a patient may affect the chances of developing TOS. Women are more likely than men to develop TOS; typically, this is observed among women aged approximately 20-50.
Physiological changes resulting from obesity or during pregnancy can also lead to changes in posture and create increased elevation of pressure on the thoracic outlet.
Causes of Thoracic Outlet Syndrome
Thoracic Outlet Syndrome (TOS), a syndrome resulting from space compression of nerves or vascular tissues where the collarbone joins with the first rib, results from several factors that cause narrowing at the inferior thoracic outlet.
- Poor posture is a common cause, with rounded shoulders and forward head posture taking up space in the thoracic outlet, compressing nerves and vascular tissues against the collarbone.
- Repetitive overhead movements with arms, performed by many athletes or those involved in physically demanding jobs, develop muscle tightness around the neck and shoulder over time and add compression in the thoracic outlet.
- Anatomical differences, such as having an extra rib (referred to as a cervical rib) or having an unusually shaped first rib or collarbone, may limit space in the thoracic outlet because of their shape and position relative to the thoracic outlet.
- Tight or hypertrophied neck and shoulder muscles can also cause compression on the nerves and vascular vessels as a result of overuse or poor movement patterns.
- Injuries such as whiplash, falls, or shoulder injuries often cause misalignment of these structures, thereby causing compression of the thoracic outlet. Additionally, scar tissue can form at the site of these injuries, contributing to the narrowing of the thoracic outlet.
- Lifestyle factors such as prolonged desk work, carrying heavy loads on the shoulders, pregnancy-related postural changes, and weight gain can further increase pressure in this area.
Complications
The complications from thoracic outlet syndrome (TOS) can occur if a correct diagnosis is delayed until the syndrome has become chronic. Furthermore, the spectrum of complications associated with TOS will increase in proportion to the amount of time that the structures affected by the compression remain compressed.
-Chronic pain and disability due to the neurogenic component of TOS represent the most common type of complication. Both the neck and shoulder (in the region of the trapezius) create chronic pain that interferes with sleep and work, as well as with daily living activities, as a result of constant nerve compression.
-If nerve compression continues for an extended period of time, the resultant damage could lead to permanent nerve damage, resulting in chronic numbness, a decrease in sensation, muscle atrophy, or a loss of coordination in the fine motor control of the hand.
-Charcoal has commonly been referred to as "the new cancer" and "the new health risk." This label is based on the understanding that charcoal leads to what has been characterized as deep vein thrombosis (DVT), resulting from TOS due to reduced blood flow, causing the formation of blood clots in your upper extremity.
-Blood clots are serious medical conditions that occur as complications of blood clots as a result of TOS. For DVT, the formation of a blood clot is caused by a lack of adequate venous return of blood in your upper extremities, creating symptoms including swelling, discoloration, and potential long-term venous injury (damage).
-Circulatory disorders can develop in thoracic outlet syndrome due to arterial compression, resulting in coldness, discoloration, and delayed wound healing, as well as potential tissue death with inadequate blood flow.
-Reduced function and strength of the affected upper limb may create limitations on the ability to lift weight, grip an object, or repetitively complete tasks that require the use of both arms, thereby adversely impacting work and athletic performance.
-Chronic pain and extended limitation of UPSA may lead to psychological issues such as stress, anxiety, and decreased quality of life.
How to Prevent Thoracic Outlet Syndrome?
Although thoracic outlet syndrome (TOS) may not always be able to be avoided due to structural issues, taking specific actions can help reduce the chances of developing symptoms and minimize those that may arise.
Good posture should be maintained by keeping shoulders back and relaxed, head aligned over the spine, and avoiding excessive slumping when working at a desk or using electronic devices for long periods.
All repetitive tasks and prolonged periods of sitting should have regular breaks to give your neck, shoulders, and upper back, the chance to stretch out and restore the movement you need to continue doing the job.
Strengthen your shoulder and neck muscles with specific exercise programs designed for improving flexibility and supporting proper alignment of the shoulder girdle and cervical (neck) spine.
Make sure your workstation has proper ergonomics, including positioning your monitor so it is at eye level, keeping your shoulders relaxed, and providing your arms with enough support to prevent slouching while at work.
Avoid carrying heavy weights on one shoulder, such as purses, backpacks, and other items, because this will place extra stress on the thoracic outlet.
Warming up prior to physical activity and using proper body mechanics while participating in sports and overhead lifting will help decrease stress on the neck, shoulders, and upper back.
Maintaining a healthy body weight is crucial because being overweight can cause changes in posture and add extra pressure to the neck and shoulder area.
When to See a Doctor?
If your neck, shoulder, or arm continues to hurt for long periods of time instead of getting better, and is accompanied by numbing, tingling, or weakness in the hand or arm, which prevents normal functioning, you should consult a doctor. Other significant symptoms include sudden swelling of the arm, skin discoloration, coldness, and a weak pulse.
Sudden swelling of the arm could indicate vascular changes and blood clots. Consulting with a doctor as soon as possible will also help rule out other diseases and prevent long-term complications by obtaining an accurate diagnosis early on.
Final Thoughts
Thoracic Outlet Syndrome (TOS) is a complex condition that can cause severe impairment to your quality of life if not diagnosed and treated. Symptoms are usually mild in the early stages; however, compressing nerves and blood vessels for a long time can lead to chronic pain, inability to carry out daily tasks, and severe complications due to vascular impairment.
Early diagnosis, adequate medical treatment, and implementing lifestyle changes will enable most people with TOS to manage their symptoms and continue to function normally in their daily lives. Awareness and prompt intervention are critical to achieving the best outcome.
