Differential Diagnosis for Unilateral Kidney Pain without Stone or Infection
Single Most Likely Diagnosis
- Chronic Pyelonephritis: This condition, characterized by recurrent or persistent infection of the kidney, can cause intermittent, unilateral kidney pain even in the absence of current infection. The pain is often due to scarring and chronic inflammation.
Other Likely Diagnoses
- Renal Artery Stenosis: Narrowing of the renal artery can cause ischemic pain, which may be intermittent and unilateral, depending on the severity of the stenosis and the presence of other vascular diseases.
- Renal Cyst: Simple renal cysts are common and can cause pain if they become large enough to exert pressure on the surrounding renal tissue or if they rupture or become infected.
- Kidney Trauma: Previous trauma to the kidney can lead to chronic pain due to scarring, hematoma, or other complications.
- Obstruction without Stone: Although stones are a common cause of obstruction, other causes like blood clots, tumors, or extrinsic compression can also lead to unilateral kidney pain.
Do Not Miss Diagnoses
- Renal Cell Carcinoma: Although less common, renal cell carcinoma can present with unilateral kidney pain and must be considered to avoid delayed diagnosis.
- Angiomyolipoma: A benign tumor of the kidney that can cause pain, especially if it ruptures or outgrows its blood supply.
- Vasculitis (e.g., Polyarteritis Nodosa): Inflammation of the blood vessels can affect the kidneys and cause pain, along with other systemic symptoms.
- Aortic Aneurysm or Dissection: Although not directly a kidney issue, an expanding aortic aneurysm or dissection can compress or obstruct renal arteries, leading to kidney pain.
Rare Diagnoses
- Medullary Sponge Kidney: A congenital disorder that can cause recurrent kidney pain due to the formation of small cysts within the kidney.
- Nephroptosis: A condition where the kidney drops down into the pelvis upon standing, which can cause intermittent pain due to stretching of the renal vessels and ureter.
- Renal Infarction: Sudden loss of blood flow to the kidney can cause severe pain and is a medical emergency.
- Loin Pain-Hematuria Syndrome: A rare condition characterized by recurrent episodes of severe flank pain and hematuria, often without an identifiable cause.