Blood in urine (hematuria)

Seeing blood in your urine can cause more than a little anxiety. Yet blood in urine — known medically as hematuria — isn't always a matter for concern. Strenuous exercise can cause blood in urine, for instance. So can a number of common drugs, including aspirin. But urinary bleeding can also indicate a serious disorder.

There are two types of blood in urine. Blood that you can see is called gross hematuria. Urinary blood that's visible only under a microscope is known as microscopic hematuria and is found when your doctor tests your urine. Either way, it's important to determine the reason for the bleeding.

Treatment depends on the underlying cause. Blood in urine caused by exercise usually goes away on its own within one or two days, but other problems often require medical care.

Symptoms

The visible sign of hematuria is pink, red or cola-colored urine — the result of the presence of red blood cells. It takes very little blood to produce red urine, and the bleeding usually isn't painful. If you're also passing blood clots in your urine, that can be painful. A lot of times, though, bloody urine occurs without other signs or symptoms.

In many cases, you can have blood in your urine that's visible only under a microscope (microscopic hematuria).

When to see a doctor
Although many cases of hematuria aren't serious, it's important to see your doctor anytime you notice blood in your urine. Keep in mind that some medications, such as the laxative Ex-lax, and certain foods, including beets, rhubarb and berries, can cause your urine to turn red. A change in urine color caused by drugs, food or exercise usually goes away within a few days. However, you can't automatically attribute red or bloody urine to medications or exercise, so it's best to see your doctor anytime you see blood in your urine.