Differential Diagnosis for Left Shoulder and Arm Pain
Single Most Likely Diagnosis
- Rotator Cuff Tendinitis or Strain: The patient's history of recent workout activity followed by shoulder tenderness and progression from dull to throbbing pain suggests an overuse injury to the rotator cuff, which is common in individuals who engage in repetitive arm movements or heavy lifting.
Other Likely Diagnoses
- Bursitis: Inflammation of the bursae around the shoulder joint could cause pain and tenderness, especially if the patient has been engaging in activities that involve repetitive motion of the shoulder.
- Muscle Strain: A strain in the muscles of the shoulder or arm could also lead to the symptoms described, particularly if the patient recently increased their workout intensity or duration.
- Thoracic Outlet Syndrome: Compression of the nerves or blood vessels that pass through the thoracic outlet could cause pain in the shoulder and arm, especially if the patient's workout involves activities that tighten the shoulder muscles.
Do Not Miss Diagnoses
- Myocardial Infarction (MI): Although less common, arm pain can be a presenting symptom of a heart attack, especially in women. The recent worsening of pain and change in character (to throbbing) necessitates consideration of cardiac causes.
- Pulmonary Embolism: While less likely, severe arm pain could be associated with a pulmonary embolism, particularly if there are other symptoms such as shortness of breath or chest pain.
- Cervical Radiculopathy: Nerve root compression in the cervical spine could cause radiating pain to the arm, and it's crucial to consider this diagnosis, especially if there are symptoms like numbness, tingling, or weakness.
Rare Diagnoses
- Pancoast Tumor: A rare type of lung cancer that can cause shoulder and arm pain due to invasion of the brachial plexus.
- Osteonecrosis of the Humeral Head: A condition where the blood supply to the bone tissue is interrupted, leading to bone death and potentially causing shoulder pain.
- Infectious or Inflammatory Arthritis: Conditions like septic arthritis or rheumatoid arthritis could cause shoulder pain, although they would typically be accompanied by other systemic symptoms or signs of infection/inflammation.