Overview. Hematuria – the presence of red blood cells in the urine – can be caused by a number of different conditions. Most of them are not serious and will quickly resolve themselves. Strenuous exercise and medications such as certain laxatives, aspirin and penicillin can allow blood to leak into the urine, for example, and these are problems that will go away on their own. Certain foods (beets, berries, rhubarb) can give the urine a red, blood-like appearance that is nothing to worry about. But because hematuria can also be a symptom of a urinary tract infection or a more serious disorder, including kidney disease and cancer, it should never be ignored.
Types and Symptoms. It’s estimated that one in 10 people will experience hematuria. The blood in the urine is not always visible to the naked eye; it can be microscopic, discovered only when the urine is being checked for other reasons. Gross hematuria, the type that can be easily seen, tends to appear as red, pink, or dark brown. It isn’t always painful, it may or may not be associated with other symptoms, and it could be persistent or intermittent. The amount of blood in the urine – or whether it is microscopic or gross – doesn’t necessarily indicate whether the problem is serious – or whether there is a problem at all. Hematuria simply means that somewhere in the genitourinary tract – either in the bladder, the kidneys, the ureters (the tubes that carry the urine into the bladder), the urethra (the tube carrying the urine out of the body), and in men, the prostate – red blood cells are leaking into the urine, requiring further investigation.
Causes. Among the most benign causes is strenuous exercise – particularly long-distance running, which tends to jar the bladder. Other common causes include certain medications, urinary tract infections (particularly common among women), urinary tract blockages, benign prostatic hyperplasia (in middle-aged and older men), kidney and bladder stones, kidney disease, physical trauma to the kidneys, a sexually transmitted disease, and certain inherited disorders such as sickle cell disease and lupus. Hematuria can also be the first sign of prostate, kidney, or bladder cancer.
Diagnosis. A physical exam, personal and family history, and variety of tests may be given in an effort to pinpoint the cause of hematuria. These include urinalysis, blood tests, imaging tests, and cystoscopy, which injects a tube with a tiny camera to take pictures inside the bladder. Sometimes the cause cannot be determined, but at minimum certain conditions can be eliminated.