Upper back pain on the left side, in the thoracic spine region, is a frequent complaint that can be alarming due to the proximity of vital organs. The pain may manifest as a dull ache, a sharp, stabbing sensation, or a persistent burning feeling between the shoulder blade and the spine. Determining the cause involves evaluating the pain’s character, onset, and accompanying symptoms. While most discomfort arises from muscular issues, the location requires considering potential internal problems.
Common Musculoskeletal Causes
Upper left back pain often originates in the muscles, ligaments, and joints supporting the spine and shoulder girdle. This area includes the rhomboid and trapezius muscles, susceptible to strain from repetitive motions or prolonged static positions. Muscle strain or a myofascial trigger point in the left trapezius can feel like a deep, localized knot radiating discomfort across the shoulder blade.
Poor posture is a leading contributor, especially for individuals sitting at a desk or driving for extended periods. Slouching causes chest muscles to shorten while upper back muscles, such as the rhomboids, are constantly stretched and stressed. This chronic overstretching leads to fatigue and pain that typically localizes to one side if the workspace setup is uneven.
Minor joint dysfunction in the thoracic spine, specifically in the facet joints, can also cause one-sided back pain. These joints can become irritated or restricted, leading to a sharp pain that worsens with movements like twisting or arching the back. Carrying a heavy bag on the left side or sleeping in a contorted position can exacerbate these imbalances. Ligament sprains are also possible following a sudden, awkward movement, resulting in a deep, aching sensation.
Internal Organ and Referred Pain
Pain felt in the upper left back may be referred pain originating from an internal organ. This occurs because the nerves supplying internal organs enter the spinal cord at similar levels to the nerves supplying the skin and muscles of the back. The brain interprets the signal as coming from the back.
Cardiac issues, such as angina or a heart attack, are the most concerning cause of referred pain to the left side. Although chest pain is the classic symptom, discomfort can radiate to the jaw, left arm, or upper back, especially between the shoulder blades. This back pain is often accompanied by shortness of breath, sweating, or pressure or tightness in the chest.
Pulmonary conditions can also manifest as pain in the upper left back, particularly pleurisy (inflammation of the lining around the lung). Irritation from conditions like pneumonia or pleurisy causes a sharp, stabbing pain. This pain worsens significantly with deep breathing, coughing, or sneezing and is usually localized to the side of the affected lung.
Pain from the digestive system may also refer to the upper back, such as pancreatitis (inflammation of the pancreas). Pancreatitis pain typically starts in the upper abdomen and radiates straight through to the back, often intensifying after eating fatty meals. A problem with the spleen, located in the upper left quadrant of the abdomen, can cause pain in the left shoulder and upper back. This pattern, known as Kehr’s sign, suggests irritation of the diaphragm and requires immediate medical evaluation.
Urgent Symptoms and Medical Attention
While most upper back pain resolves with rest and conservative care, certain accompanying symptoms signal a need for immediate medical attention. Any sudden, severe pain, especially if unrelenting or not relieved by changing position, should be evaluated. Pain accompanied by non-musculoskeletal symptoms often suggests an internal cause.
Red flag symptoms include back pain combined with chest pressure, lightheadedness, or difficulty breathing, which may indicate a cardiac or pulmonary event. Fever, chills, or unexplained weight loss may point toward an underlying infection in the spine or a systemic illness. Neurological symptoms like numbness, tingling, or weakness in the arms or legs require prompt assessment, suggesting potential nerve compression.
If the pain is clearly muscular, initial self-care involves applying ice for acute inflammation or heat to relax tight muscles. Gentle stretching and temporary avoidance of aggravating activities can provide relief. However, if the pain follows trauma, persists for more than a few days, or is accompanied by any systemic or neurological warning signs, a consultation is necessary for proper diagnosis and treatment.