Pain in the left arm and shoulder can occur in anyone, although certain medical conditions and personal habits can increase the risk of developing this type of pain. People with minor to moderate pain in the left shoulder and arm may experience relief through protection of that part of the body, rest, ice packs, compression and elevation. Strong to severe pain may require medical treatment. Consider this information derived from the Mayo Clinic and the National Library of Medicine about the causes of left shoulder and arm pain.
People with joint inflammation caused by ankylosing spondylitis, rheumatoid arthritis or osteoarthritis may develop pain in the shoulder or arm. Bursitis is an abnormal inflammation of fluid between joints that may cause pain in the shoulder or arm that flares up intermittently. People with avascular necrosis (death of bone tissue) of the shoulder or arm may also experience pain.
People with certain medical conditions may experience pain in the left shoulder or arm. Those who develop sudden shoulder or arm pain along with symptoms such as shortness of breath, anxiety or sweating may be having a heart attack. People with long-term illnesses such as bone cancer or multiple sclerosis may also develop shoulder or arm pains.
People with bacterial or viral infections may develop shoulder or arm pain if the infection invades the blood and bones. Sepsis, which is the result of staph bacteria invading the bloodstream, can cause septic arthritis of the shoulder and arm. People who develop shingles can have complications such as postherpetic neuralgia, which can cause pain in the shoulder or arm.
People who are injured while playing sports or as a result of violence or other trauma may develop pain in the left shoulder and arm. Rotator cuff injuries, torn cartilage and dislocated shoulders are common injuries that result from physical activity and can cause pain in the shoulder or arm. A fractured or broken bone in the arm or shoulder also can be a cause of left arm or shoulder pain.
People with injuries to the neck or back that damage the spinal cord may develop arm or shoulder pain. Inflammation of the muscles around the nerves in the arm, which is called polymyositis, can also cause pain in the shoulder and arm that may recur without warning. People with injuries to the brachial plexus can cause pain throughout the shoulder, arm and hand and may result from an injury or occur in a baby during vaginal delivery.
People who overuse their left shoulders or arms may experience pain that gets better with rest. Overuse may be a result of repetitive motions such as pitching a ball or typing on a keyboard for many hours a day. People who attempt to do more strenuous exercises than the muscles can handle, such as weightlifting, may also experience left arm or shoulder pain.