What would happen if a kidney stone blocked one of the collecting ducts?

If a kidney stone blocks one of the collecting ducts, it can lead to a condition called obstructive uropathy. Here's what might happen:

1. Impaired Urine Flow: The collecting duct is a small tube that helps transport urine from the nephrons (functional units of the kidneys) to the renal pelvis. When a kidney stone blocks the collecting duct, it obstructs the flow of urine downstream, causing a buildup of urine in the affected kidney.

2. Increased Pressure: As urine accumulates in the kidney, it can lead to increased pressure within the collecting system and the kidney itself. This condition is known as hydronephrosis. Elevated pressure can damage the delicate structures of the kidney and impair its function.

3. Pain: Obstruction of the collecting duct can cause severe pain in the back or side, often referred to as flank pain. The pain may be intermittent or constant and can range from mild to excruciating.

4. Infection Risk: Urine stasis (stagnation) due to the blockage can increase the risk of urinary tract infections (UTIs). Bacteria can multiply in the trapped urine, leading to inflammation and infection in the kidney, collecting ducts, and other parts of the urinary system.

5. Decreased Kidney Function: Prolonged obstruction of the collecting duct can lead to a decline in kidney function. If the blockage persists and is not treated promptly, it can cause significant damage to the kidney tissue, potentially leading to chronic kidney disease (CKD).

6. Additional Complications: In severe cases, if the obstruction affects both kidneys or if there are other underlying conditions, it can result in more serious complications such as kidney failure, sepsis (a life-threatening systemic infection), and even permanent kidney damage.

It's important to seek medical attention if you experience persistent flank pain, difficulty urinating, or any other concerning symptoms that might indicate a kidney stone or urinary tract obstruction. Early diagnosis and prompt treatment are essential to minimize the risk of complications and ensure proper kidney function.