Left Upper Back: Medical Terminology and Clinical Significance
The left upper back is medically termed the "left upper thoracic region" or "left interscapular region," referring to the area between the spine and the left scapula (shoulder blade) in the upper-to-mid thoracic spine (approximately T1-T7 vertebral levels). 1
Anatomical Terminology
- Thoracic back pain (TBP): Pain localized to the thoracic spine region, which extends from the base of the neck to the bottom of the rib cage 1
- Interscapular pain: Pain specifically located between the shoulder blades, which includes the left upper back area 2, 3
- Left paraspinal region: The area immediately adjacent to the spine on the left side, involving the thoracic paraspinous muscles 4
- Medial scapular border region: The area along the inner edge of the left shoulder blade, a common site for upper thoracic pain 2, 3
Clinical Context and Differential Diagnosis
When evaluating left upper back pain, the location corresponds to the upper thoracic spine (T1-T7), which requires systematic assessment to distinguish benign musculoskeletal conditions from serious underlying pathologies. 2
Common Musculoskeletal Causes
- Myofascial pain: Benign pain originating from thoracic paraspinous soft tissues, the most common cause in otherwise healthy individuals 4, 2
- Thoracic disc herniation: Most commonly occurs below T7, but can affect upper levels, presenting with thoracic midback pain in 76% of cases, typically in patients aged 30-50 years 4, 2
- Facet joint arthropathy: Pain aggravated by prolonged standing, hyperextension, or rotation of the thoracic spine 5
- Dorsal scapular nerve entrapment: A rare cause of upper thoracic and medial scapular pain that can mimic other pathologies 3
Serious Pathologies Requiring Immediate Consideration
- Aortic dissection: Must be considered first when thoracic back pain is sudden onset, severe, or tearing in quality, especially with hypertension or after physical exertion 4
- Cardiac ischemia: Can cause referred pain to the left upper thoracic region 2, 6
- Malignancy: Primary or metastatic tumors commonly affect the thoracic spine 4, 2
- Spinal infection: Osteomyelitis, discitis, or epidural abscess with fever, recent infection, or immunosuppression 4, 2
- Compression fractures: Particularly in patients >65 years, on chronic steroids, or with known osteoporosis 4, 2
Clinical Assessment Framework
The American College of Radiology recommends a systematic approach that prioritizes red flag screening before attributing pain to benign musculoskeletal causes. 1, 4
Red Flags Requiring Urgent Evaluation
- History of cancer, unexplained weight loss, or age >50 years 4, 2
- Fever, recent infection, immunosuppression, or IV drug use 4, 2
- Significant trauma history or midline tenderness with fracture risk factors 4, 2
- Progressive neurologic deficits, myelopathy, or radiculopathy 1, 4
- Sudden onset severe pain suggesting vascular catastrophe 4
Imaging Considerations
- No imaging indicated: Acute thoracic back pain (<4 weeks) without red flags, myelopathy, or radiculopathy 1, 4
- X-ray thoracic spine: Initial study for fracture risk factors with midline tenderness 4
- MRI thoracic spine without contrast: Initial imaging of choice for myelopathy or radiculopathy 1, 2
- MRI with and without contrast: For suspected malignancy or infection 2
Common Clinical Pitfall
A critical error is failing to consider referred pain from intrathoracic pathology (cardiac ischemia, pulmonary embolism), gastrointestinal conditions (peptic ulcer, pancreatitis), or renal pathology when evaluating left upper back pain. 2, 6 The left upper back location specifically raises concern for cardiac ischemia, which can present as interscapular pain without classic chest pain symptoms. 6