Causes of tingling sensations in the left shoulder include cervical spondylosis, cervical radiculopathy, chemical burns, thermal burns and brachial plexus nerve injury, notes the Virginia Spine Institute and WebMD. Cervical spinal stenosis, multiple sclerosis, median nerve injuries or ulnar nerve injuries are other potential causes.
Left-arm tingling is also a known symptom of heart attack, notes Health magazine. In regard to heart attack, the left-arm tingling may expand to a tingling feeling down the right arm or down one of the legs.
In most cases, the sensation is not limited to the shoulders and may extend to the bicep, elbow or forearm, notes WebMD. If the sensation is brief then the tingling may be due to sitting or standing for too long in one position, according to the U.S. National Library of Medicine. A persistent or consistent tingling sensation in the left arm should be diagnosed as soon as possible by a doctor.
In order to treat the tingling sensation, doctors ask patients to describe the tingling sensation, according to the Virginia Spine Institute. Knowing whether or not the sensation is ongoing and consistent or intermittent helps doctors evaluate the situation. It is also important to know whether or not there are any other sensations in any other parts of the body, such as a pinched feeling in the wrist, which may signal carpal tunnel syndrome.