Seeing blood in your urine can be alarming. While in many instances the cause is harmless, blood in urine (hematuria) can indicate a serious disorder or cancer of the urinary tract.
Blood that you can see is called gross hematuria, and produces pink, red or cola-colored urine due to the presence of red blood cells. It takes little blood to produce red urine, and the bleeding usually isn't painful. Bloody urine often occurs without other signs or symptoms.
Various benign reasons for hematuria include urinary tract infections, urinary tract stones, enlarged prostate or kidney injury. Hematuria typically requires evaluation by urologist to rule out a cancer-related cause.
Evaluation for hematuria includes imaging of the kidneys and cystoscopy, which is camera evaluation of the bladder taking about 1 minute in the urology clinic.