Differential Diagnosis for Right Flank Pain

The differential diagnosis for right flank pain can be categorized into several groups based on the likelihood and potential severity of the conditions.

• Single Most Likely Diagnosis

  • Nephrolithiasis (Kidney Stones): This is often the most common cause of acute flank pain, especially if the pain is severe and radiates to the groin. The pain is typically colicky in nature, meaning it comes and goes in waves.

• Other Likely Diagnoses

  • Pyelonephritis: An infection of the kidney, which can cause flank pain, fever, and other urinary symptoms. It's more common in women and those with urinary tract abnormalities.
  • Musculoskeletal Strain: Overuse or injury to the muscles in the flank area can cause pain, especially if there's a history of heavy lifting or strenuous activity.
  • Herniated Disk: A herniated disk in the lower back can cause flank pain, especially if the disk is pressing on a nerve that affects the flank area.

• Do Not Miss Diagnoses

  • Appendicitis: Although appendicitis typically presents with right lower quadrant abdominal pain, in some cases (especially if the appendix is retrocecal), it can cause right flank pain. Missing this diagnosis can lead to perforation and severe complications.
  • Pulmonary Embolism: In rare cases, a pulmonary embolism can cause referred pain to the flank area, especially if the embolism is large and affects the upper parts of the lung.
  • Aortic Dissection: A tear in the aorta can cause severe, tearing pain that can radiate to the flank area. This is a medical emergency that requires immediate attention.

• Rare Diagnoses

  • Renal Cell Carcinoma: A type of kidney cancer that can cause flank pain, although it's typically a more chronic and less severe pain than that caused by kidney stones.
  • Pheochromocytoma: A rare tumor of the adrenal gland that can cause episodic hypertension and flank pain.
  • Epididymitis or Orchitis: Inflammation of the epididymis or testis, which can cause pain that radiates to the flank area, especially if the condition is severe or involves the right side.