Differential Diagnosis for Interscapular Pain and Left Shoulder Pain when Stressed and Anxious

• Single Most Likely Diagnosis
  • Musculoskeletal strain or tension: This is the most likely diagnosis given the symptoms are triggered by stress and anxiety, which can cause muscle tension leading to pain in the interscapular region and left shoulder.
• Other Likely Diagnoses
  • Costochondritis: Inflammation of the cartilage that connects the ribs to the breastbone can cause chest pain that may radiate to the back and shoulders, potentially worsening with stress.
  • Thoracic outlet syndrome: Compression of the nerves and/or blood vessels that pass into the thoracic outlet (the space between your collarbone and first rib) can cause pain in the shoulders and back, which might be exacerbated by stress-induced muscle tension.
  • Gastroesophageal reflux disease (GERD): Although primarily causing heartburn, GERD can sometimes cause referred pain to the back and shoulders, and stress can exacerbate symptoms.
• Do Not Miss Diagnoses
  • Myocardial infarction (heart attack): Although less common in younger individuals, myocardial infarction can present with atypical symptoms including back or shoulder pain, especially in women, and must be considered, particularly if the pain is severe or accompanied by other symptoms like shortness of breath or arm pain.
  • Pulmonary embolism: Sudden onset of chest pain or back pain, especially if accompanied by shortness of breath, could indicate a pulmonary embolism, which is life-threatening and requires immediate medical attention.
  • Aortic dissection: A tear in the aorta's inner layer can cause severe, tearing chest pain that radiates to the back, which is a medical emergency.
• Rare Diagnoses
  • Pancoast tumor: A type of lung cancer located at the top of the lung that can cause shoulder and back pain due to local invasion of nerves and structures, but this would be a rare cause of the described symptoms.
  • Spinal or rib fractures: Stress fractures or osteoporotic fractures could cause localized pain but would typically have a more distinct onset and possibly other symptoms like limited mobility or trauma history.