Don’t Ignore This One Serious Symptom

You expect to see yellow in the bowl. But what does it mean if you spot red instead?

Blood in you urine is called gross hematuria, and it could signal health problems as mild as a bladder infection or as serious as cancer. The color of the blood may range from slight pink to brown to thick, dark clots.

You should seek treatment even if you just see blood once, says Brian Norouzi, M.D., a urologist with St. Joseph Hospital in Orange, Calif. Put it off too long and the root cause can become more difficult to treat. 

Here’s what you need to know about peeing blood—and what you and your doctor should do about it. 

Why Do You Pee Blood?
Potential causes of blood in your urine include the following, Dr. Norouzi says.

1. Injuries: Any kind of trauma—say, taking a blow to your kidneys—can cause you to pee blood. If your kidney is cut or torn by the force, the blood may seep into the tissue around it, before making its way into your urine. 

2. Infections: When germs invade your urinary tract, like with bladder or prostate infections, your body’s natural inflammatory response to fight them off can cause bleeding, Dr. Norouzi says.

3. Kidney stones: These stones create friction as they rub against the insides of your organs, much the way new shoes cause a blister. And the tender tissue on your insides bleeds much more easily than your tough outer layer of skin.

4. Cancer: Cancerous cells in your bladder, kidneys, or urethra—the tube that carries urine out of your body—can also disrupt healthy tissues so much they start bleeding. Plus, tumors grow quickly and demand a large blood supply. The new, tiny vessels that sprout up to feed them often break and leak blood, too.

5. Strenuous exercise: Exercising vigorously—especially long-distance running—can also produce visible bleeding. Doctors aren’t sure why, but think it occur because such activities cause minor damage to your bladder or cause your body to break down red blood cells.