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, typically presenting with severe, colicky pain that may radiate to the groin. The pain is usually accompanied by nausea, vomiting, and sometimes hematuria.

• Other Likely Diagnoses

  • Pyelonephritis: An infection of the kidney, which can cause flank pain, fever, and other symptoms like dysuria and frequent urination.
  • Musculoskeletal Strain: Overuse or injury to the muscles in the flank area can cause significant pain.
  • Herniated Disk: A herniated disk in the lower back can cause flank pain, especially if it compresses nerves that radiate to the flank area.

• Do Not Miss Diagnoses

  • Appendicitis (if the appendix is retrocecal): Although appendicitis typically presents with right lower quadrant pain, a retrocecal appendix can cause right flank pain.
  • Pulmonary Embolism: Can cause sudden onset of flank pain if the embolism affects the upper parts of the lung, though this is less common.
  • Aortic Dissection or Aneurysm: These are life-threatening conditions that can cause severe flank pain, among other symptoms.
  • Ectopic Pregnancy: In women, especially those of childbearing age, ectopic pregnancy can cause flank pain and is a medical emergency.

• Rare Diagnoses

  • Pheochromocytoma: A rare tumor of the adrenal gland that can cause episodic hypertension and flank pain.
  • Renal Cell Carcinoma: A type of kidney cancer that might cause flank pain, though it's more commonly associated with a palpable mass, hematuria, and systemic symptoms.
  • Spinal Infection (e.g., osteomyelitis or discitis): Infections of the spine can cause flank pain, especially if they involve the lower thoracic or upper lumbar regions.