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What Causes Blood in Urine?


Updated May 20, 2014

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Question: What Causes Blood in Urine?
After I urinated the other day, I noticed that I had blood in my urine. It was on the tissue and also in the toilet. Is blood in urine a symptom of cancer? What can cause blood to be in my urine?
Answer: Finding blood in your urine can be a frightening experience. Any time you discover it, it is important to see your doctor. Blood in the urine (hematuria) is a symptom of many diseases and conditions and often require treatment. The good news is that in most cases, cancer is not responsible. Blood in the urine is more likely to be caused by a much less serious problem.

Causes of Blood in Urine

There are many reasons why blood may appear in your urine. A urinary tract infection is a common culprit, as are kidney stones. Other causes can include taking certain medications, diabetes, hypertension, and other diseases. Injury or strenuous exercise can even cause blood in the urine.

Blood in the urine can be a symptom of some types of cancer. Bladder cancer and kidney cancer can both cause blood to appear in the urine. Prostate cancer can as well, but it is not common.

If you have seen blood in your urine, report it to your doctor, even if it has gone away. Many times, blood can be present in the urine, but we can't see it. This is called microscopic hematuria and means that the blood cannot be seen by the naked eye.

There are also instances where it looks like blood may be in the urine, but it really isn't blood. For women, an example would be menstrual bleeding that flows from the vagina during urination, giving the false appearance of blood in the urine. Red foods like beets and rhubarb can alter the color of urine, but only usually if you eat a lot of them. Medications can also cause the color of urine to change, giving an appearance of bloody urine.

If you are unsure whether you have blood in your urine, report it to your doctor. A urinalysis is all that is needed to determine if blood is present in the urine. Depending on any other symptoms you may have, your doctor may ask to collect the urine by catheter. Urinating in a cup is a much more common means of providing a urine sample, however.


American Cancer Society. How is Bladder Cancer Diagnosed? Bladder Cancer: Detailed Guide. 07 July 2010. Accessed October 15, 2010. http://www.cancer.org/Cancer/BladderCancer/DetailedGuide/bladder-cancer-diagnosis

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