Obstructive uropathy is a structural or functional hinrance of normal urine flow, sometimes leading to renal dysfunction (obstructive nephropathy). Symptoms, less likely in chronic obstruction, are pain radiating to the T11 to T12 dermatomes, anuria, nocturia, or polyuria. Diagnosis is based on results of bladder catheterization, ultrasonography, CT scan, cystourethroscopy, or pyelography, depending on the level of obstruction. Treatment, depending on cause, may require prompt drainage, instrumentation, surgery (eg, endoscopy, lithotripsy), hormonal therapy, or a combination of these modalities.