Some possible causes of left arm numbness can be nerve damage, stroke and heart attack. A main cause of numbness in either arm is nerve damage that occurs in medical conditions, such as carpal tunnel, cubital and radial tunnel syndromes. In each of these conditions, a specific nerve located in the arm is compressed or pinched, according to WebMD.
Carpal tunnel syndrome develops when the median nerve in the wrist area of the arm is affected, states Mayo Clinic. Cubital tunnel syndrome involves the ulnar nerve found in the elbow region. Radial tunnel syndrome is related to damage of the radial nerve, which travels along the forearm and elbow regions. The possible symptoms of these syndromes are pain and numbness in the specific region of the arm that is affected. For example, cubital tunnel syndrome can cause numbness and weakness in the elbow area but can also affect the hand in more severe cases.
A possible symptom of both stroke and a heart attack is numbness in either arm, reports the National Institutes of Health. In the case of heart attacks, numbness can develop in both arms and shoulders. However, there are other different symptoms associated with these medical conditions. A heart attack, can present symptoms, such as breathing problems and pain in the chest or abdominal area. Stroke victims can experience vision problems and difficulty with speech.
The main cause of either a heart attack or stroke is the blockage of an artery that leads either to the heart or brain. Some risk factors for both of these conditions can be hypertension and high cholesterol levels.