The Most Common Causes of Left Arm Numbness

Having a numb left arm or experiencing an uncomfortable sensation in it can be quite disturbing. Medicine often associates it with having a myocardial infarction. There are many other causes though.
The Most Common Causes of Left Arm Numbness

Last update: 14 June, 2021

Left arm numbness is an abnormal sensation that may happen at some point during your life. It’s a symptom many find disturbing, as we tend to associate it with the possibility of a heart attack.

Numbness in one or both arms is actually a fairly common sensation and may be due to several factors. Indeed, it could be cardiovascular. So, pay attention to it, as it might require a trip to the ER.

Things to watch out for include the presence of other symptoms in addition to the numbness, such as neck pain, chest pain, anxiety, vomiting, and so on. Also, pay attention to whether the pain increases with physical activity or if it occurs after you’re stuck in an uncomfortable posture.

So what could be the reason for left-arm numbness? Well, considering how common it is, we’ll detail some of its possible causes as well as some tips on what to do about it. Keep in mind that this is only a guideline and it’s important to consult a doctor ASAP.

The possible causes of left arm numbness

A numb left arm can be due to both cardiac and non-cardiac reasons. This is why it’s important to learn to recognize the difference between one event and the other. In fact, this is crucial when seeking medical attention.

Cardiac origin

Coronary heart disease is often a cause of left-arm numbness. It may even manifest in both arms or in the hands. In addition to this, patients may feel:

  • Oppressive or retrosternal pain, or of difficult localization in the chest (angina pectoris)
  • Pain radiating to the neck area or in the epigastrium (pit of the stomach) or interscapular or in the jaw, teeth, or shoulders
  • A feeling of heaviness and tension

These symptoms may be due to physical exertion, stress, or exposure to cold. Generally, the pain will last for a few minutes (two to five minutes) and may subside when the triggering stimulus disappears.

However, it doesn’t always occur in this way and may also appear during rest. Similarly, it’s possible to experience other symptoms such as:

  • A sensation of imminent death
  • Anxiety
  • Sweating
  • Nausea and vomiting
  • Abdominal pain
  • Belching
  • Shortness of breath
  • Fainting

Go to your nearest ER or call an ambulance for immediate medical attention if you suspect a heart attack. Keep in mind that the sooner you attend to the situation, the better the prognosis will be.

A woman with a pain on her chest.
Experiencing numbness in the left arm could be a sign of a cardiac problem, although this doesn’t apply to all cases.

Non-cardiac origin

Cervical osteoarthritis is a common degenerative condition of the cervical spine — also known as cervical spondyloarthritis. It usually occurs after the age of 40 and worsens with age. In fact, many people over the age of 60 have it.

To date, we know that factors such as smoking, excessive lifting, or poor posture can worsen it. It often manifests as neck and shoulder pain, headaches, and pain in the occipital region. Moreover, it can lead to limited movement.

These kinds of pain can appear or worsen with certain activities or head movements. Muscular weakness is also common. Note that some patients don’t experience pain or numbness in the arms despite the signs of cervical osteoarthritis on imaging studies.

It’ll be important to assess whether the numbness is associated with pain (especially in the neck and head region, and under what circumstances it occurs) in order to guide the diagnosis. The medical staff will also inquire about any accidents or injuries that may have previously occurred.

The physical examination will be orientative. However, the doctor will probably request imaging studies to either confirm or rule out the presence of osteoarthritis. Generally, they’ll use a conservative treatment that includes analgesics, physiotherapy (exercises, self-massage, and stretching), postural changes, etcetera. Rarely will it require invasive treatments.

A woman massaging her wrist.
Diseases such as arthritis may also be behind a feeling of weakness and left-arm numbness. It requires a medical diagnosis.

Other non-cardiac causes of left arm numbness

  • Poor sleeping posture
  • Carpal tunnel syndrome
  • Tennis elbow
  • Golfer’s elbow
  • Diabetic neuropathy 
  • Cubital tunnel syndrome
  • Radiculopathy

Keep in mind that the numbness will be on the affected side if the cause is non-cardiac (osteoarthritis, tennis elbow, etc.). Thus, it could be on the left or right side or both.

As often happens, the symptoms can manifest atypically and lead to diagnostic doubts that a timely medical consultation will need to clear up.

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