What Causes Arm Numbness?
Arm numbness can be a symptom of many diseases, disorders, or conditions that restrict blood flow or injure nerves.
Circulatory causes of arm numbness
A lack of blood supply to the area can cause arm numbness. Conditions that can impede blood flow include:
- arteriovenous malformation, which is an abnormal connection between an artery and a vein
- Buerger’s disease, which causes progressive inflammation and clotting of arteries and veins
- frostbite or extremely cold temperatures
- peripheral artery disease, which is a narrowing of arteries due to a buildup of fat and cholesterol on the artery walls
Orthopedic causes of arm numbness
Arm numbness may also occur due to moderate to serious orthopedic conditions that injure or damage the nerves. Though some nerves can be damaged by acute injury, others may be susceptible to damage due to their proximity to bones or joints, which makes compression more likely.
Possible orthopedic causes of arm numbness include:
- broken bones or a cast that is too tight
- carpal tunnel syndrome
- cervical spondylosis, a degenerative joint disease in the neck
- herniated disk
- neck or cervical spinal cord injury
- nerve entrapment or nerve pressure, such as from sleeping on your arm
Neurological causes of arm numbness
Other conditions that can affect the nerves and cause arm numbness include:
- alcohol use disorder
- diabetic neuropathy, consisting of nerve damage due to high blood sugar levels associated with poorly controlled diabetes
- heavy metal poisoning, such as lead poisoning
- hypothyroidism, which is an underactive thyroid gland
- multiple sclerosis, a disease that affects the brain and spinal cord
- peripheral neuropathy, a disorder of the peripheral nerves
- spinal cord tumor
- systemic lupus erythematosus, a connective tissue disorder in which the body attacks its healthy cells and tissues
- transverse myelitis, a neurological disorder that causes inflammation of the spinal cord
- vitamin B12 deficiency
Arm numbness may occur with other symptoms or a combination of symptoms depending on the cause. It can be preceded by a pins-and-needles or burning sensation called paresthesia. Paresthesia often results from sustained nerve pressure, which can lead to numbness.
Other symptoms that might occur with arm numbness include:
- cold arm or fingers
- itching feeling
- muscle spasms
- neck pain
- sensitivity to touch
- shoulder, arm, hand, or finger pain
To diagnose your condition, your doctor will likely ask questions such as:
- Where are you feeling numb?
- When did the numbness start?
- How long does the numbness last?
- Are there any activities that cause the numbness?
- Are you experiencing other sensations, such as pain, burning, or itchiness?
- Do your arms, hands, or fingers feel cold or warm?
In addition, imaging tests may reveal broken bones, tumors, or other structural irregularities that may interfere with nerve function or blood flow.
The treatments for arm numbness vary depending on the underlying cause.
In some cases, adjusting your environment could relieve arm numbness. For example, people who experience arm numbness from factors such as sleeping on their arms could benefit from adjusting their sleeping positions.
A warmer environment would provide relief for people experiencing frostbite or extremely cold temperatures.
Conditions such as carpal tunnel syndrome or cervical spondylosis may require surgery to relieve arm numbness. People with circulatory conditions such as peripheral artery disease or Buerger’s disease may need medication to improve blood flow.
A doctor can advise on the best treatment for you.
Depending on the cause, arm numbness may disappear quickly or persist. For example, numbness from extremely cold temperatures will fade once you move to a warmer environment.
Chronic arm numbness generally indicates some nerve damage.
Complications associated with arm numbness depend on the cause. Seek treatment if you experience numbness or other symptoms to avoid complications and permanent damage.
Also, following your doctor’s treatment plan may help you avoid complications such as:
- arm disability
- inability to perform daily tasks
- loss of strength
- permanent loss of sensation
- chronic pain
- reduced quality of life
Numbness can be a symptom of many conditions. Talk with a medical professional about any numbness that is persistent, recurrent, or causes you concern.
Seek emergency medical attention if arm numbness occurs with the following:
Stacy Sampson, D.O., reviewed the answers to some common questions about arm numbness.
When should I worry about arm numbness?
Contact a doctor if your arm numbness is persistent, recurrent, or occurs with other concerning symptoms. Seeking treatment may help prevent permanent loss of sensation or chronic pain.
Is a numb arm a sign of a stroke?
Many conditions, some temporary and others chronic, can cause arm numbness. Contact a doctor for diagnosis and treatment.