Hydronephrosis

Hydronephrosis is caused by obstruction of urine drainage from the kidney, leading to urine accumulation and retention, resulting in increased intrarenal pressure, gradual dilation of the renal pelvis and calyces, and atrophy and destruction of the renal parenchyma. Hydronephrosis is the dilation of the renal pelvis and calyces accompanied by renal tissue atrophy due to urinary tract obstruction. Stenosis or obstruction of any part of the urinary tract, as well as abnormal neuromuscular function, can impede urine flow, causing urinary obstruction. Above the obstruction, pressure gradually increases due to impaired urine drainage, leading to dilation of the lumen, ultimately resulting in renal hydronephrosis, dilation, thinning of the renal parenchyma, and decreased renal function. If bilateral obstruction occurs, uremia develops with severe consequences.