Sir, Myself 35 Years Old. For Primary Hypertension I Was

Sir, myself 35 years old. For primary hypertension I was adviced USG KUB.For this I went in morning with empty stomach n full bladder....before test I repeatedly drank lot of water n urinate also....every time I urinate partially n drank more water to compensate the water loss due to urination...this I have done before USG KUB...At the time of test I forcefully stopped the urge to urinate......test is conducted n doc ask me that if I have abdomen pain, to which I denied....my test shows "mild hydronephrosis in right kidney".. Sir plz tell if it is due to overdrinking n forcefully stopping urine or some major problem..urea/creatinine is 24/0.9...and urine microscopy test shows numerous calcium oxalate crstal.. Kindly suggest..is it dangerous ..can it be cure with medicine