What is the medical term for swelling of one or both kidneys due to urine flow backup?

The medical term for swelling of one or both kidneys due to urine flow backup is hydronephrosis. This condition occurs when there is an obstruction in the urinary tract, preventing urine from properly draining from the kidney. As urine accumulates, it causes the renal pelvis and calyces to stretch and swell, leading to enlargement of the kidney.

In contrast, nephromegaly refers to the general enlargement of the kidneys, which may not necessarily be due to urine flow obstruction. Pyelonephritis is an infection of the kidney, often caused by bacteria, and is characterized by inflammation rather than swelling from urine accumulation. Cystitis, on the other hand, is the inflammation of the bladder, frequently due to infection, and does not involve the kidneys directly. Understanding these distinctions is crucial in medical terminology and anatomy.