Differential Diagnosis for Right Side Flank Pain Radiating to Back with Painful Urination

• Single Most Likely Diagnosis

  • Nephrolithiasis (Kidney Stones): This condition is characterized by the formation of stones in the kidneys, which can cause severe flank pain that radiates to the back and is often accompanied by painful urination (dysuria). The pain can be exacerbated by movement and can vary in intensity.

• Other Likely Diagnoses

  • Pyelonephritis: An infection of the kidney, which can cause flank pain, fever, and painful urination. The pain typically occurs on one side and can radiate to the back.
  • Urinary Tract Infection (UTI): While more commonly associated with lower urinary tract symptoms, upper UTIs can cause flank pain and painful urination.
  • Musculoskeletal strain: Strain in the muscles of the back or flank area can cause pain that radiates to the back, though it's less likely to be associated with painful urination.

• 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 present with flank pain. Painful urination might not be a primary symptom, but it's crucial to consider appendicitis due to its potential for severe complications if not promptly treated.
  • Renal Infarction: A blockage of the blood supply to the kidney can cause severe flank pain and might be associated with nausea, vomiting, and fever. It's less likely to cause painful urination directly but is a critical condition that requires immediate medical attention.
  • Ectopic Pregnancy: In women, an ectopic pregnancy can cause severe abdominal or flank pain and is a medical emergency. While it might not directly cause painful urination, it's a condition that cannot be missed due to its high risk of complications.

• Rare Diagnoses

  • Renal Cell Carcinoma: A type of kidney cancer that can cause flank pain and hematuria (blood in the urine), which might lead to painful urination. It's less common and typically presents in older adults.
  • Polycystic Kidney Disease (PKD): A genetic disorder characterized by the growth of numerous cysts in the kidneys, which can cause flank pain, hematuria, and occasionally painful urination due to associated urinary tract infections or kidney stones.
  • Retroperitoneal Fibrosis: A rare condition characterized by the proliferation of fibrous tissue in the retroperitoneum, which can encase and obstruct structures such as the ureters, leading to flank pain and potentially painful urination.