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Left Arm Numbness

Over the last several days you noticed that you have left arm numbness.  Your mind is wildly looking for answers.  What causes it? When should you be concerned about it?  What are the treatment options?  Let’s dig in.

Sitting or lying on the couch too long while watching a game or series can cause left arm numbness which promptly resolves with movement.  This is typically caused by restricted blood flow or excessive pressure on a nerve.  If numbness in the arm is abrupt in onset or persists, this is a warning sign!

What Causes Left Arm Numbness?

Left-arm numbness can be frightening.  There are many causes, and the major ones include:

1. Thoracic Outlet Syndrome

Thoracic outlet syndrome is a group of disorders that involve the compression and irritation of the nerves, arteries, and veins in the lower neck and chest (1).  Pain is a major symptom and can be intermittent or constant and varies in severity and quality.  The pain can involve the lower neck, collar bone, and hand.   Left-arm numbness can also be present.

2. Cervical Nerve Irritation

The neck is composed of seven building blocks called vertebral bodies.  Sandwiched between each of the building blocks is a disc.  They are important shock absorbers in the neck.   Nerves exit the spine at each level sending important information to the arm and hand.  Unfortunately, cervical discs can be injured by trauma, degeneration, infection, and arthritis (2).  Common cervical disc injuries are bulges or herniations both of which can cause cervical nerve irritation or compression.  This compression can result in a number of symptoms which include left arm numbness.

3. Cervical Stenosis

The spinal cord extends from the brain down to the low back.  It is enclosed in the spinal canal which contains spinal fluid and the spinal cord.  If the spinal canal becomes narrowed the spinal cord can become irritated or compressed.  This compression is called stenosis and causes a number of symptoms including left arm numbness (3).  To learn more about cervical stenosis please click in the video below.


A heart attack occurs when there are insufficient blood flow and oxygen to the heart.  This can occur as a result of reduced or blocked blood flow due to a blood clot or plaque.   A heart attack is a serious medical emergency.  Symptoms include chest discomfort, lightheadedness, nausea, and shortness of breath.  Patients may have arm pain or numbness.  If you or somebody with you has these symptoms immediate evaluation is required. CALL 911 immediately.


A stroke occurs when there is an interruption of blood flow to the brain (4).  There are two major types of strokes:  ischemic and hemorrhagic.  In an ischemic stroke,  blood clots or fatty deposits within the blood vessel restrict blood flow to the brain.  In a hemorrhagic stroke, one or more blood vessels rupture.  In both cases, there is impaired brain blood flow.  Brain cells start dying.  Symptoms vary in character and intensity.

FAST is an important acronym to help detect and enhance responsiveness to the needs of a person having a stroke

Facial Drooping

Arm weakness or numbness

Speech difficulties

Time.  If any of the above symptoms are present time is critical. CALL 911

6. Nerve Injury

Nerves pass through muscles, tendons, ligaments, and boney surfaces and they coarse through the arm to the hand. They are susceptible to compression, irritation, or injury at multiple points.  Symptoms include pain tingling, weakness, and arm numbness.  Common sites of compression include the elbow and wrist. Common peripheral nerve injuries include:

Carpal Tunnel Syndrome: Numbness and tingling in the hand and arm due to compression of the median nerve at the level of the wrist.  It is the most common peripheral nerve compression condition in the upper arm.  It is a condition of middle-aged individuals and affects females more often than males (5). You may experience numbness after carpal tunnel surgery.

Cubital Tunnel Syndrome:  involves compression of the ulnar nerve at the level of the elbow.  Symptoms include forearm pain, weakness n the hand, and numbness and tingling in the ring and fifth finger. Cubital tunnel syndrome is the second most common peripheral nerve entrapment neuropathy in the upper limb (6).  Risk factors for cubital tunnel syndrome include diabetes, obesity, trauma, and holding a tool for prolonged periods with elbow bent (7).

Cervical Radiculopathy

Common Cervical Radiculopathy symptoms include neck pain, arm pain, shoulder pain radiating down arm to fingers, numbness, tingling, and weakness. Cervical Radiculopathy is a clinical condition in which a nerve or nerves in your neck become irritated or compressed. It is also known as ” a pinched nerve,” The causes are discussed below. It can affect individuals of any age with peak prominence between ages 40-50 years of age. Cervical Radiculopathy is due to spinal nerve inflammation, irritation, or compression. The most common causes of Cervical Radiculopathy are: Disc Injury – The disc is an important shock absorber. Unfortunately, it is susceptible to injury.

Read More About Cervical Radiculopathy

Lateral Epicondylitis / Tennis Elbow

Lateral epicondylitis otherwise known as tennis elbow is an overuse injury involving the extensor muscles that originate on the bony prominence (epicondyle) on the outside (lateral) aspect of the elbow. It is more properly termed tendinosis that specifically involves the origin of the extensor carpi radialis brevis muscle. In a study, Nirschl and Pettrone attributed the cause of lateral epicondylitis to be tearing in the origin of the extensor carpi radialis brevis (ECRB) muscle (1). The extensor carpi radialis brevis (ECRB) muscle originates from the lateral epicondyle. It functions to move the wrist so that the hand moves away from the palm and towards the thumb.

Read More About Lateral Epicondylitis / Tennis Elbow

Medial Epicondylitis / Golfer’s Elbow

Golfer’s elbow involves tears in the ulnar collateral ligament and pain or soreness on the inside of the elbow. The bony bump you feel there is the medial epicondyle of the humerus (upper arm bone). There are five forearm muscles that attach at this point, all of which are involved in helping to flex or rotate the forearm and wrist. Pain can get worse when you throw a ball, grip a dumbbell, turn a screwdriver, and other movements that involve the fingers, hand, wrist, and/or elbow. Tennis elbow is similar, however, it refers to the outside of the elbow, at the lateral epicondyle.

Read More About Medial Epicondylitis / Golfer’s Elbow

Pinched Nerves in the Back

We talk a lot about leg pain stemming from a pinched or irritated nerve in the lower back. And, indeed, that’s what our physicians are traditionally taught in medical school—a pinched nerve in the lumbar spine typically presents as a symptom in the leg. However, what if you have some butt pain but no pain or other symptoms in the leg? Does this mean it couldn’t be a pinched nerve? Not so fast. Turns out a pinched low back nerve doesn’t always have to be accompanied by leg symptoms. Let’s start by taking a look at how the back is structured.

Read More About Pinched Nerves in the Back

Slipping Rib Syndrome

Slipping Rib Syndrome can be incredibly painful and is often misdiagnosed. It is also known as rib dislocation, rib subluxation, Tietze syndrome, Davies–Colley’s syndrome, rib-tip syndrome, painful rib syndrome, costochondral separation, and clicking or moving rib syndrome. It is very common for athletes involved in contact sports to get a slipped rib. Trauma causes stretching and sometimes tearing of the ligament attachments of the rib, creating instability. We also see this in many of our motor vehicle accident patients, caused by the seat belt and/or airbag. Once damaged, it can take several weeks to resolve (4-12 weeks). After 3 months, if the rib continues to…

Read More About Slipping Rib Syndrome

Spinal Stenosis

Spinal stenosis is the narrowing of the central spinal canal and is a cause of significant pain and disability.  Common causes of spinal stenosis include disc protrusion, facet overgrowth and ligamentum flavum thickening.  Surgery is often chosen when conservative therapies fail despite the lack of convincing evidence that it is a superior treatment option.  Are there alternatives to back surgery for spinal stenosis?  Yes. Regenexx DDD utilizes precise platelet injections into the facets, muscles, and ligaments to treat the lumbar stenosis, treating all of the components of the issue, which is crucial. Spinal stenosis is often an age-related condition attributed…

Read More About Spinal Stenosis

Thoracic Outlet Syndrome

The thoracic outlet is an area around the collar bone where the nerves that come from your neck meet up with the blood vessels from your heart and together supply the entire upper extremity (shoulder and arm). These blood vessels (subclavian artery and vein) and nerves (brachial plexus) travel from the base of your neck to your armpit (axilla) and are considered the “thoracic outlet”. Now that you know what the thoracic outlet is, what is thoracic outlet syndrome? Simply listening to a patient’s history and completing a physical examination is all that is needed to diagnose TOS. But more involved imaging such as X-rays…

Read More About Thoracic Outlet Syndrome
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When Should I be Concerned 

Unexplained arm numbness requires immediate attention.  If left arm numbness is abrupt in onset and not due to trauma or compromised posture time is of the essence.  Call 911!

Treatment Options for Left Arm Numbness

Treatment depends upon the underlying cause of the arm numbness.  Left-arm numbness is a warning sign that requires attention.  As noted above unexplained numbness requires immediate attention.

At the Centeno-Schultz Clinic, we are experts in the treatment of left-arm numbness due to cervical nerve irritation, cervical stenosis, thoracic outlet syndrome, and peripheral nerve injuries. When appropriate first-line treatment should involve conservative care including physical therapy and stretching. Steroid injections should be avoided as they are toxic to orthopedic tissue and can accelerate damage (8)

Surgery for Cervical Stenosis and Thoracic Outlet Syndrome is major surgery and associated with significant risks.  These risks include infection, nerve damage, failure to fuse, and Adjacent Segment Disease.  A previous blog details the risks and nonsurgical treatment options for Cervical Stenosis.

Treatment options include stem cells and platelets. At the Centeno-Schultz Clinic, there are different PRP treatment options for different conditions.  Platelet lysate is ideal for the treatment of nerve injuries.  It super concentrates growth factors found in platelets.  To learn more about platelet lysate and growth factors please click on the video below.

In Conclusion

Left-arm numbness can be alarming.  The major causes include Thoracic Outlet Syndrome, cervical nerve injury, Cervical Stenosis, heart attack, stroke, and nerve injury.  Unexplained left arm numbness requires immediate attention.  Treatment options depend upon the underlying cause.  The Centeno-Schultz Clinic Physicians are experts in the non-surgical treatment of left arm numbness due to thoracic outlet syndrome, cervical stenosis, cervical nerve injury, and peripheral nerve compression.  Treatment options include PRP and stem cells.  Left-arm numbness is a warning signal that requires attention.  If abrupt in onset and not due to trauma or compromised posture time is of the essence.

If you are or a loved one is suffering from progressive left arm numbness due to cervical, thoracic injuries or peripheral nerve compression, please contact us.   Schedule a Telemedicine consult with a board-certified physician who can review your history, studies, and provide you the best nonsurgical treatment option.  Listen to your body as it is warning you!


1.Jones MR, Prabhakar A, Viswanath O, et al. Thoracic Outlet Syndrome: A Comprehensive Review of Pathophysiology, Diagnosis, and Treatment. Pain Ther. 2019;8(1):5-18. doi:10.1007/s40122-019-0124-2

2..Peng B, DePalma MJ. Cervical disc degeneration and neck pain. J Pain Res. 2018;11:2853-2857. Published 2018 Nov 14. doi:10.2147/JPR.S180018

3.Meyer F, Börm W, Thomé C. Degenerative cervical spinal stenosis: current strategies in diagnosis and treatment. Dtsch Arztebl Int. 2008;105(20):366-372. doi:10.3238/arztebl.2008.0366

4.French BR, Boddepalli RS, Govindarajan R. Acute Ischemic Stroke: Current Status and Future Directions. Mo Med. 2016;113(6):480-486.

5.Aroori S, Spence RA. Carpal tunnel syndrome. Ulster Med J. 2008;77(1):6-17.

6.Cutts S. Cubital tunnel syndrome. Postgrad Med J. 2007;83(975):28-31. doi:10.1136/pgmj.2006.047456.

7. Descatha A, Leclerc A, Chastang JF, Roquelaure Y; Study Group on Repetitive Work. Incidence of ulnar nerve entrapment at the elbow in repetitive work. Scand J Work Environ Health. 2004;30(3):234-240. doi:10.5271/sjweh.784.

8. Wernecke C, Braun HJ, Dragoo JL. The Effect of Intra-articular Corticosteroids on Articular Cartilage: A Systematic Review. Orthop J Sports Med. 2015;3(5):2325967115581163. Published 2015 Apr 27. doi:10.1177/2325967115581163

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