Thanks for your quey
both the ureters can be blocked only when there is a pathology at their junctional point like in the bladder or urethra or prostate in male. If there is a bladder tumor
or urethral stricture
or benign hypertrophy of prostate they can lead to bilateral hydronephrosis
and bilateral changes.
Kidney pain may be caused by renal stone itself even in the absence of urteral patholgy. Renal cell carcinoma
may also cause pain. Bilateral hydronephrosis on few occassions may cause pain. Please do consult a urologist
and go for cystoscopy or ascending cysto-urethrogram for better delineation of the pathology causing bilateral hydronephrosis.