What Causes Blood to be in Urine After Exercising?

Hematuria, or blood in the urine, can result from a number of causes, including exercise 3. Although hematuria is more common in long distance runners, this condition can occur after any type of prolonged, intense physical activity. In most cases, it is not cause for serious concern. See your doctor for an accurate diagnosis if you have blood in your urine after exercising.

Causes of Exercise-Induced Hematuria

The exact cause of exercised-induced hematuria remains unclear, but there are several potential causes 3. Trauma to the bladder walls during exercise can cause bruising and bleeding, which could cause blood in your urine. Exercise might also interfere with the process of filtering the urine from the bloodstream, allowing red blood cells to mix with it. During intense exercise, the body can redirect blood flow away from the kidney, causing red blood cells to leak into the urine. The release of hemoglobin -- the protein that gives red blood cells their color -- into your urine during exercise may also cause hematuria 3.

Underlying Conditions

While the blood in your urine is most likely from exercise, it could indicate the presence of other conditions with this symptom. For this reason, you should see your doctor to rule them out. Possible underlying causes include urinary tract infections, kidney stones or other conditions affecting the kidney, an enlarged prostate or certain types of cancer.

Prevention

No surefire way exists to prevent bloody urine after exercise but certain measures might help. Trauma to the bladder walls might intensify when it is empty. Avoid fully emptying your bladder before exercise to prevent the walls from jarring against each other. Stay well-hydrated during exercise – dehydration will cause blood to be shunted from the kidneys, into your urine. If you continue to experience blood in the urine when exercising, do not become too distressed – as long as you have ruled out other causes, it should not cause any damage.

When to See a Doctor

Seek medical attention if your see blood in your urine after exercise. See your doctor right away if symptoms such as low back pain or fever accompany the blood in your urine -- you may have an infection.