Numbness of the Arm

Numbness down part of or the entire arm can be caused by a variety of underlying medical conditions or factors.  A healthcare professional for proper and thorough evaluation is critical to obtain a diagnosis and treatment plan.  Here are some common causes of numbness down the arm:

1. Nerve Compression or Pinching:
   – Cervical Radiculopathy: Compression or irritation of the nerves in the neck (cervical spine), often due to herniated discs, arthritis, or spinal stenosis, can lead to numbness and tingling that may extend into the arm.  This can be from trauma or from a degenerative (arthritis) condition with minimal history of injury.
2. Brachial Plexus Injury:
   – Trauma or injury to the brachial plexus, a network of nerves that controls arm and hand movement, can result in arm numbness, pain, and weakness.  This is typically from a major trauma or recent viral illness.
3. Peripheral Neuropathy:
   – Conditions such as diabetes, alcohol abuse, vitamin deficiencies, or certain infections can damage peripheral nerves, leading to numbness that can affect the entire arm.  Typically these are slow developing problems over time. 
4. Circulatory Issues:
   – Reduced blood flow to the arm due to conditions like a blood clot blocking an artery, or vasculitis, can result in numbness.  These can be a sign of cardiovascular disease and require emergent evaluation.
5. Thoracic Outlet Syndrome (TOS):
   – TOS occurs when blood vessels or nerves in the space between the collarbone and first rib become compressed, leading to arm numbness and weakness.  This is typically associated with certain positions or activities and is more intermittent in nature.
6. Repetitive Motion or Overuse:
   – Engaging in repetitive activities or overusing the arm muscles can lead to a temporary condition known as “overuse syndrome” or “repetitive stress injury,” which can cause numbness.  This is usually a specific nerve that is compressed with a specific area.  For example, repetitive trauma to the wrist (like typing) can cause carpal tunnel syndrome, which involves compression of the median nerve resulting in numbness in the thumb, index, and long finger, whereas compression of the ulnar nerve at the elbow can cause radiating numbness and pain from the elbow into the pinky and ring fingers.
7. Autoimmune Disorders:
   – Conditions like multiple sclerosis (MS) or Guillain-Barré syndrome can affect nerves and lead to numbness and other neurological symptoms.  These usually present with a constellation of symptoms more than numbness.
8. Stroke or Transient Ischemic Attack (TIA):**
   – Although less common, a stroke or TIA can affect the brain and lead to numbness in the arm or other neurological symptoms.  Also this usually presents with a constellation of symptoms with weakness and/or speech difficulty and facial asymmetry.
9. Medications or Toxins:
   – Certain medications or exposure to toxins can cause nerve damage and numbness as a side effect.  This is usually not limited to one extremity.
10. Other Medical Conditions:
    – Various other medical conditions, such as hypothyroidism, Lyme disease, or systemic lupus erythematosus (SLE), can lead to numbness in the arm.

To determine the cause of numbness in your entire arm, a healthcare provider may conduct a physical examination, order diagnostic tests like imaging (MRI, CT scan) or nerve conduction studies, and consider your medical history. Treatment will depend on the underlying cause. It’s crucial not to ignore persistent numbness, especially if it’s sudden or accompanied by other concerning symptoms like weakness, difficulty speaking, or changes in consciousness, as these could be signs of a medical emergency like a stroke and these patients should immediately seek attention in an emergency room.  At Total Orthopedics and Sports Medicine, we have orthopedic and neurosurgical specialists who can evaluate, diagnose, and treat your condition.