<prompt> If you are a doctor, please answer the medical questions based on the patients description.Problem: presence of red blood cells R.B.C in urine sample Hi, my mom is 59 years old and she recently had her routine blood and urine checkup. Fortunately, every thing was normal except for presence of 6-7 RBC in her urine. She also had kidney and bladder sonography which indicated a 20mm cyst fluid-filled and simple in her right kidney. Bladder sono also showed that about 20 ml urine residue in her bladder. I am wondering whether the blood is related with the kidney cyst or it maybe related to a problem in bladder. Many thanks  <response>: HelloThanks for query. Your mother has been detected to have simple Renal cyst in her Rt kidney and 20 ml of residual urine in bladder. It is common to have residual urine in females after the age of menopause due to incomplete emptying of bladder secondary to Post Menopausal Urethral Stenosis which gets infected causing CystitisThe presence of RBC in urine is due to infection of the bladder Cystitis that she has and not due to cyst These cysts are benign in nature. Get her urine culture done and start appropriate antibiotics as per culture report to control the bladder infection. Chat Doctor. 