What Causes Left Back & Shoulder Pain?
The left back and shoulder region includes many structures that can cause pain, including your shoulder joint, ribs, shoulder blade and various muscles, tendons, ligaments and nerves. Pain in the left back and posterior shoulder can caused by injuries, including joint sprains and muscle strains.
Pain in the shoulder and nearby upper back is a common problem. This region contains many structures that can cause pain, including the shoulder joint and various muscles, tendons, ligaments and nerves. Pain often results from injuries to muscles or tendons. It may also be caused by medical conditions, such as arthritis, cancer or even a heart attack.
Muscle Injury
Injuries to muscles are a common cause of pain in the left shoulder and back. Muscle strains occur when muscles are stretched beyond their normal limits, causing muscle fibers to tear. Muscles can also be injured by direct trauma to the area. Both types of injuries can cause inflammation, redness, soreness or bruising. Trigger points -- areas that are especially sensitive when touched -- may develop in injured muscles, further increasing pain in the region, according to a 2011 study in "BMC Musculoskeletal Disorders."
Moist heat, massage, gentle stretching and temporary rest often decrease pain caused by muscle injuries. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin) and naproxen (Aleve), may also be useful. Treatments for trigger points include physical therapy and injections of local anesthetic.
Tendon and Ligament Injuries
Tendons and ligaments around the shoulder joint can also be overstretched, leading to tears -- tendon tears are called strains and ligament tears are known as sprains. Torn rotator cuff tendons, caused by an acute injury or gradual degeneration over time, are one of the most common shoulder disorders.
Both tendon and ligament injuries can produce pain in the shoulder and nearby upper back. The pain is typically an aching sensation at rest, which becomes sharp with arm movement. It may also cause a person to awaken at night. Ligament and tendon pain often improves with the same therapies as for muscle injuries.
Arthritis
Arthritis involving the shoulder is a common cause of shoulder and adjacent upper back pain. Osteoarthritis is caused by breakdown of the cartilage that acts as cushion between the bones in the shoulder joint. It becomes more common with age. About one-third of people over 60 have at least some shoulder arthritis, according to an article published in "Arthritis" in 2013. Rheumatoid arthritis -- an autoimmune condition in which the immune system attacks tissue within the joints -- usually begins earlier in life and may even occur in childhood.
Pain caused by shoulder arthritis is often sharp with arm movement and aching when resting or trying to sleep. Pain due to both types of arthritis may decrease with rest, NSAIDs and moist heat. Rheumatoid arthritis is also treated with other medications, such as disease-modifying anti-rheumatic drugs (DMARDs). Joint injections and surgery may be required for both types of arthritis.
Spinal Disorders
Pinched -- or compressed -- nerves exiting the spine are another cause of pain in the upper back and shoulder. This occurs with disorders of the cervical spine -- the part of the spine located in the neck. Nerve compression is often the result of a herniated disc or overgrowth of bone in the area due to natural degeneration that occurs with aging.
Shoulder and upper back pain caused by nerve compression is often a burning or stabbing pain. It may worsen with movement of the neck. Numbness, pins and needles sensations and weakness in the shoulder or arm may accompany the pain. Treatment often includes limiting neck movement, physical therapy or medications. Surgery is sometimes required.
Other Conditions
Heart problems, such as angina or a heart attack, may sometimes cause pain in the left shoulder and adjacent back. Other symptoms of a heart attack may include chest pain or pressure, pain in the left arm or jaw, shortness of breath, nausea, vomiting, sudden fatigue, dizziness or fainting.
Lung cancer sometimes produces pain in the left upper back and shoulder. Cancer in the bones around the shoulder -- cancer that either begins in the bones or travels there from another area such as the breast -- may also cause pain in the region. Lung cancer often causes a cough and shortness of breath. Unexplained weight loss, fever and fatigue may occur with many types of cancer.
Seeking Medical Attention
If you have pain in your left shoulder and nearby back, visit your doctor to determine the cause. See your doctor promptly if you have symptoms suggestive of cancer or nerve compression. Seek immediate attention if you experience symptoms suggestive of a heart attack. Also seek immediate medical care if you notice symptoms of nerve compression in both arms or legs or any changes in bowel or bladder control, as these indicate that a spinal disorder may be compressing your spinal cord.
Reviewed and revised by Mary D. Daley, M.D.