A condition of urine obstruction in the renal pelvis, which distends from stasis, and is a common cause of renal failure.

Obstruction of urine flow causes hydronephrosis. Obstructions are either congenital or acquired. If the obstruction is above the level of the bladder, then there is unilateral involvement of the ureter and the kidney. Obstruction at or below the level of the bladder brings about bilateral involvement. In adults, the obstruction is mainly from stones in the tract, pelvic tumors, or urethral narrowing.

Pain brought on by distention is a primary symptom. A stone lodged in the ureter causes renal colic. This is an excruciating, continuous, severe pain that radiates from the lower abdomen to the genital area. Flank pain when voiding is significant of bladder-ureteral back-flow (reflux). Increased urea in the blood (azotemia) occurs when there is lack of overall excretion function. Anuria with acute renal failure suggests complete bilateral obstruction. Hydronephrosis, either unilateral or bilateral, combined with fluid volume expansion, usually results in notable hypertension due to increased release of renin. Difficulty in urinating, urinary tract infections (UTI), pain, and changes in urine volume are common complaints in obstructive disorders.

Physical examination, including methods of palpation and percussion, can reveal distention. Urine is examined for hematuria, pyuria, and bacteria (bacteriuria). Abdominal x-rays, ultrasound, urography, computed tomography (CT) scan, and magnetic resonance imaging (MRI) may all be used to locate stones or obstructions.

It is necessary to start early treatment of any urinary tract obstruction complicated by infection in order to prevent kidney damage and sepsis. Antibiotics are given to overcome infection. Drainage tubes are placed to temporarily relieve obstruction. A poorly functioning infected kidney may need to be removed.

A favorable prognosis is dependent on the amount of kidney damage that has occurred. A completely obstructed, infected kidney can be totally destroyed in days, and would necessitate removal. Every effort should be made to drain, and try to restore as much kidney function as possible.

• May be entitled to special monthly compensation where the Veteran has a single service-connected disability rated as 100% with additional service-connected disability or disabilities independently ratable at 60% or more, which are separate and distinct from the 100% service-connected disability and involves different anatomical segments or bodily systems. See 38 CFR 3.350(i)(1) – Special Monthly Compensation (SMC).

• The new criteria for the Genitourinary Disease and Conditions body system became effective November 14, 2021.  Review both current and historic criteria prior to any reduction for disabilities established before that date.  38 CFR 3.951(a)

• When evaluating any claim involving loss or loss of use of one or more creative organs, refer to 38 CFR 3.350 of this chapter to determine whether the Veteran may be entitled to special monthly compensation. Footnotes in the schedule indicate conditions which potentially establish entitlement to special monthly compensation; however, there are other conditions in this section which under certain circumstances also establish entitlement to special monthly compensation.