Is blood in urine 7mm3 worrisome for a 65 years old woman? urine test, culture , ct scan of bladder, all came out negative.wha t else could it be?

Need cytoscopy: Blood in urine, if found repeatedly, warrants evaluation by a urologist. A urologist will usually do a test called a cystoscopy, in which the doctor looks directly at the inside of your bladder with a tiny microscope. If the lining of the bladder is inflammed, then the problem could be hemorrhagic cystitis. The urologist can also rule out bladder cancer with cystoscopy.

Hematuria: The work up should inculde a Urinalysis with C&S, CT Urogram (to assess the whole collecting system including the kidneys and ureters and bladder and Urethra), and finally a Cystoscopy which will asses the superior aspect of the Bladder that may not be completely visualized on the CT Urogram. If all these tests come back normal, may be simple irritation of the urethra or somewhere else to monitor.

See my comment: She needs to have a visual look into her bladder (cystoscopy) to rule out tumor