Differential Diagnosis for Sudden Onset Left Mid Back Pain
Single Most Likely Diagnosis
- Musculoskeletal strain: Given the sudden onset of moderate pain with movement and breathing, and in the absence of trauma, a musculoskeletal strain is a plausible explanation. The pain's location in the left mid back and the patient's reluctance to take deep breaths to minimize discomfort support this diagnosis.
Other Likely Diagnoses
- Pulmonary embolism: Although the oxygen saturation is 98%, pulmonary embolism should be considered, especially if there are risk factors such as recent travel, surgery, or family history. The pain associated with pulmonary embolism can be sudden and worsen with deep breathing.
- Pneumonia: Community-acquired pneumonia could present with sudden onset of back pain if the infection involves the lower lobes of the lung, causing pleuritic chest pain that radiates to the back.
- Costochondritis: Inflammation of the cartilage that connects the ribs to the sternum can cause sharp pains in the chest or back that worsen with movement or deep breathing.
Do Not Miss Diagnoses
- Aortic dissection: A life-threatening condition where there is a tear in the inner layer of the aorta. It can present with sudden, severe back pain that may radiate to the chest or abdomen. Although less likely, missing this diagnosis can be fatal.
- Pneumothorax: A collapsed lung can cause sudden chest pain that worsens with deep breathing. It's crucial to consider this, especially if there's a history of lung disease or recent procedure.
- Myocardial infarction: Although more commonly associated with chest pain, myocardial infarction can occasionally present with back pain, especially in women or diabetic patients.
Rare Diagnoses
- Pancreatitis: Inflammation of the pancreas can cause severe back pain, usually in the upper abdomen that radiates to the back. It's less likely given the description but should be considered if there are risk factors such as gallstones or alcohol abuse.
- Spinal infection or tumor: Less common causes of back pain that could present acutely, though typically with additional symptoms such as fever, weight loss, or neurological deficits.
- Herpes zoster (shingles): Can cause severe pain in a dermatomal distribution before the rash appears, which might be mistaken for musculoskeletal pain if not recognized early.