Differential diagnosis of thoracic spine pain

1. Mechanical and musculoskeletal causes

• Non-specific mechanical pain: postural overload, prolonged sitting, repetitive rotation/reaching, deconditioning.
• Paraspinal muscle strain or myofascial pain: focal tenderness, spasm, pain reproduced by movement or palpation.
• Thoracic facet joint pain / costotransverse or costovertebral joint dysfunction: unilateral paraspinal or rib-adjacent pain, worse on extension, rotation, deep inspiration, or coughing.
• Thoracic disc degeneration or disc herniation: axial pain, sometimes band-like thoracic radicular pain; a large central lesion can cause myelopathy.
• Rib injury or stress fracture, costochondritis, intercostal muscle strain.
• Scheuermann kyphosis, scoliosis, hyperkyphosis, or other spinal deformity.

2. Trauma and bone disease

• Acute vertebral fracture: major trauma or minor trauma in a person with osteoporosis.
• Osteoporotic vertebral compression fracture: abrupt focal pain, vertebral tenderness, loss of height or progressive kyphosis.
• Pathological fracture: due to metastatic disease, multiple myeloma, lymphoma, or other bone lesion.
• Metabolic bone disease: osteomalacia, Paget disease.

3. Neurologic and spinal canal causes

• Thoracic radiculopathy: burning, shooting, or “belt-like” pain in a dermatomal distribution; may be caused by disc disease, foraminal stenosis, herpes zoster, diabetes, or tumor.
• Thoracic myelopathy / spinal cord compression: gait disturbance, leg weakness or stiffness, hyperreflexia, sensory level, or bowel/bladder dysfunction. Causes include a large disc herniation, tumor, epidural abscess/hematoma, stenosis, or deformity.
• Herpes zoster: unilateral dermatomal burning pain, potentially before the rash appears.
• Less common: syringomyelia, demyelinating disease, spinal vascular malformation.

4. Inflammatory rheumatic disease

• Axial spondyloarthritis / ankylosing spondylitis: onset usually before age 40, morning stiffness, nocturnal pain, improvement with activity rather than rest; may coexist with uveitis, psoriasis, inflammatory bowel disease, or enthesitis.
• Psoriatic arthritis and other spondyloarthritides.
• Rheumatoid arthritis is less commonly centered in the thoracic spine but can contribute to inflammatory pain or associated osteoporosis.

5. Infection

• Vertebral osteomyelitis / discitis
• Spinal epidural abscess
• Tuberculous spondylitis (Pott disease), especially with epidemiologic risk factors

6. Malignancy

• Vertebral metastases: especially from breast, lung, prostate, kidney, thyroid, and gastrointestinal cancers.
• Multiple myeloma, lymphoma, or primary spinal tumor.
• Epidural metastatic disease can produce cord compression.

7. Referred visceral pain

• Cardiac/aortic: acute coronary syndrome, aortic dissection, thoracic aortic aneurysm.
• Pulmonary/pleural: pulmonary embolism, pneumonia, pleurisy, pneumothorax, lung tumor.
• Gastrointestinal: esophagitis, esophageal rupture, peptic ulcer disease, pancreatitis, biliary disease.
• Renal: pyelonephritis, renal colic.
• Other: mediastinal disease.

Red flags requiring urgent evaluation

• New leg weakness, numbness, gait imbalance, a sensory level, hyperreflexia, or bowel/bladder dysfunction
• Fever/systemic illness, immunosuppression, injection drug use, or recent bloodstream infection
• Major trauma, or minor trauma with osteoporosis/steroid exposure
• Previous or suspected cancer, weight loss, or relentless/night pain
• Sudden severe “tearing” chest or back pain, syncope, chest pain, shortness of breath, or pleuritic symptoms
• Rapidly worsening, non-mechanical pain or marked focal bony tenderness

1. Thoracic degenerative joint disease / facet or costovertebral osteoarthritis
   Often causes stiffness after lying still, improving after getting up and moving. Local pain with rotation, extension, deep breathing, or pressure beside the spine supports this.
2. Paraspinal muscular stiffness or myofascial pain
   Common with sleeping posture, reduced activity, kyphosis, or prolonged daytime posture. It should improve fairly quickly with gentle movement, heat, and changing position.
3. Osteoporotic vertebral compression fracture
   Important to exclude in a woman aged 65, particularly with known osteopenia/osteoporosis, prior fragility fracture, low body weight, smoking, long-term steroid use, aromatase-inhibitor therapy, or even minor lifting/twisting. Pain is often focal and can be worse on getting up, standing, or loading the spine. It may occur without a memorable injury.
4. Inflammatory spinal disease
   Morning stiffness that improves with exercise and is worse with rest suggests inflammatory pain. However, new axial spondyloarthritis at 65 is less typical because inflammatory back pain classically starts before age 45. Consider it more if stiffness lasts over 30 to 60 minutes, symptoms wake her in the second half of the night, and there is psoriasis, uveitis, inflammatory bowel disease, heel pain, or a prior history of sacroiliitis.
5. Less common but important: malignancy or spinal infection
   These are less likely if pain occurs only in the morning and eases with activity, with no systemic symptoms. Still, thoracic pain newly beginning after age 50 warrants review if persistent, because thoracic pain can occasionally reflect vertebral fracture, tumor, or infection. Thoracic pain guidance includes osteoporosis/fracture, inflammatory disease, infection, and malignancy among key considerations.

Practical interpretation

• Brief stiffness on waking, easing within 15 to 30 minutes: mechanical stiffness, osteoarthritis, muscle/postural causes more likely.
• Stiffness lasting >45 to 60 minutes, improving markedly with activity but not rest: evaluate for inflammatory disease.
• Sudden focal pain, height loss, a new hunched posture, or pain after a small lift/fall: assess promptly for a compression fracture.

Arrange medical assessment soon if

Seek urgent care today for

• Fever, night sweats, unexplained weight loss, history of cancer
• Severe or steadily worsening pain, especially pain unrelated to movement
• Leg weakness, gait difficulty, numbness around the trunk or legs
• New bladder or bowel changes
• Chest pain, shortness of breath, or severe sudden upper-back pain