What to Think if You See Blood in the Toilet

Both benign conditions and cancer can make your pee bloody.

Woman flushing toilet
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 Anyone who has ever seen blood in their urine or blood turning the toilet water red as or after they pee, understands how startling this site is.  But the first thing to know is that it is extremely uncommon for you to lose much blood in your urine.  In reality, it takes very little blood to make the bowl turn fairly red (not unlike the effect of only a drop or two of food coloring).  The second thing you should know is that not all blood in the urine (called “hematuria”) means cancer, as several benign conditions can also declare themselves through urinary blood alone.

  And third, regardless of any embarrassment that you may (unnecessarily) feel in sharing this concern with anyone, you should always see your physician partner, even if you only experience one episode of hematuria, both to make certain that you don’t have a cancer and also to understand what if any treatment you might need for a benign cause of urinary bleeding.

Let’s “take it from the top.”  Urine is created in our left and right kidneys before traveling through long, narrow tubes called the left and right ureters.  The ureters empty into the single bladder, a very distensible tissue bag which sits centrally in your pelvis (it’s what you sense when you really need to pee!).  When you urinate, the muscles within the bladder wall contract, squeezing urine out of your bladder and through a single, narrow tube, the urethra, which releases your urine to the outside world.  In men, the urethra passes through the prostate gland before traveling through the penis.

Blood in the urine can come from any of these urinary system structures, and depending on the specific organ or tissue, you and your doctor may consider benign and/or malignant sources.  So let’s quickly go through the different conditions for each site which can cause (only) blood in the urine.

When doctors discuss kidney (“renal”) cancer, we often also include cancers of the ureter (which originate within the kidneys), calling the latter cancers of the “renal pelvis.”  While lumped together, the two cancer types originate in different areas of the kidney from different cell types (distinguishable by a pathologist) and have different treatments.

  Renal and renal pelvis cancers are (together) the ninth most commonly diagnosed malignancies in the United States.  Fortunately, they respond well to treatment, and greater than 73% of patients are alive five years after diagnosis.  Blood in the urine may be the only symptom of a kidney or renal pelvis cancer.  However, a common benign condition can also present as hematuria alone:  kidney stones.  The solid, crystalized, little formations of urinary minerals (not all of which are so little) develop within the tubes of the kidney, where they may remain or from where they often travel with the urine.  A stone that remains in the kidney, and a stone that is small enough to silently pass all the way into the bladder, may present as hematuria alone (the little concretion rubs and erodes on the tissue lining).  Larger stones tend to lodge within the narrow ureter, and while this also commonly produces hematuria, the urinary blood is always overshadowed by the waves of severe flank and/or groin pain.

  Thus when it comes to hematuria and the kidneys, we think of benign stones versus malignant tumors.

Bladder cancer is the fifth most common malignancy and (fortunately) is also highly treatable, with a five-year survival rate of over 77%.  Because the bladder is basically an elastic balloon, even a big tumor rarely causes pain or interferes with urine flow.  But tumors bleed, and painless hematuria is the most common initial symptom of bladder cancer.  Benign bladder polyps less commonly may also bleed (some of these can later transform into cancers if not removed).  And as I previously mentioned, small benign kidney stones can silently reach the bladder and also cause painless hematuria.  So in the bladder, we think cancer versus benign stone or polyp.

Both cancer of the urethra (which carries urine from the bladder to the outside world) and benign conditions which produce hematuria are rare. 

Prostate cancer is the third most common malignancy.  Most cancer are small and asymptomatic, detected by a physician performing a digital rectal exam or evaluating an elevated blood PSA.  However, hematuria may be the only symptom, particularly of more advanced tumors.  The most common benign condition, BPH, does not cause hematuria.  And while urinary blood can rarely be seen with benign prostatitis, it is always associated with pain.  Thus when it comes to your prostate, isolated hematuria is most concerning for a cancer.

So should you find your toilet water pink or red one day, don’t panic (it may be a benign condition), but definitely own your health and see your physician.

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