An enlarged or swollen kidney is usually the result of a backflow of urine from the bladder to the kidney, kidney stones or a blockage of the ureter due to a tumor, scarring or congenital abnormalities, according to MedlinePlus. Medical professionals have not established the causes of kidney swelling during pregnancy.
Kidneys swell when urine fails to drain from the kidney to the bladder due to an obstruction or blockage, claims the National Kidney Foundation. Swelling is usually caused by underlying illnesses or risk factors such as blood clots, scarring tissue due to previous surgery or injury or a urinary tract infection. Bladder, colon, prostate or cervical cancer may also cause one or both kidneys to swell. Swelling may also be the result of an enlarged prostate.
Medical professionals typically use an ultrasound to confirm diagnoses of enlarged kidneys, states the National Kidney Foundation. Physicians may also diagnose the condition with computerized tomography, X-rays or magnetic resonance imaging. The condition is treated by addressing the underlying causes or risk factors. In patients with severe blockage, physicians may need to drain excess urine using a catheter or a special tube that drains urine from the kidneys. Severe cases of blockage may lead to kidney damage and kidney failure.