Mild hydronephrosis, what can be the cause?

Dear Ask The Doctor: Hi a am 25 old male i have pain in lower side of my back both side a done some lab test bun 16 createne 2.16 h Uric acid 7.95 h NA 141 K 4.1 fbs 95.3 the ultra sound report: mild hydronephrosis in the left kidny the doc gave ibuprofen and 2 days off 6 days gone and am sill in pain no swelling or diabetes or hypertension

Dear Sahem: The pain that you are experiencing could be probably due to the hydronephrosis of the left kidney. A unilateral hydronephrosis is caused due to kidney stones or when there is back flow of urine from the bladder into the kidneys. There also may be evidence of infection.

The treatment will depend on the underlying cause and i would advise for further investigations like CT and IVP to rule out stones.