Introduction
The medical term for blood in urine is “hematuria”. The “heme” refers to the hemoglobin in red blood cells and the “uria” means that it is in the urine. Also, when we talk about blood in the urine, we really mean red blood cells in the urine.
Recognizing the Symptoms
Urine is normally a light yellow to dark amber, depending on how concentrated it is. The most common symptom of blood in the urine a change in urine color because it takes very little blood in the urine to turn it pink or red. However, many people have blood in their urine without a change in the color and have no symptoms.
Making the Diagnosis
The easiest way to make a diagnosis is to use a urine dipstick because it is very sensitive for hemoglobin. However, a positive dipstick doesn’t always mean there is blood in the urine. To confirm the diagnosis, your doctor needs to find red blood cells in your urine using a microscope.
Recognizing the Different Types
There are two different types of blood in urine depending on how much blood is in the urine. If there is enough blood that it is obvious to the naked eye, it is called gross hematuria. If you need a microscope to see it, then it is called microscopic hematuria.
Where It Could Be Coming From
Blood in the urine can come from anywhere in the urinary tract system from the kidneys to the urethra. Other potential sources include contamination for the genital system (especially with menstruation) and the gastrointestinal tract.
Knowing the Causes
There are hundreds of causes for blood in urine. The most common causes are infections, kidney stones, kidney cysts, and urinary tract tumors. Other important causes are kidney diseases that affect the glomeruli and blood vessels.
Working up of Blood in Urine
It is important to initially assess how long the blood loss has been present and if there is an obvious and benign cause. If the bleeding is persistent and not immediately obvious, the workup usually starts with an assessment of risk factors by taking a good history and physical exam. A series of blood and urine tests are usually ordered as well. Depending on the results of this initial assessment, certain radiology studies or invasive procedures may be necessary.
Radiology Studies for Blood in Urine
There are number of radiology studies that can be ordered in the workup of blood in the urine. The most common are a kidney ultrasound and intravenous pyelography (IVP). However, for a number of reasons, the CT scan is rapidly becoming the test of choice. A follow-up MRI is not infrequently ordered if there is a question about something looking cancerous.
Special Procedures for Blood in Urine
Because of the concern for bladder cancer with blood in the urine, people are risk usually get a cystoscopy to directly look at their bladder. If there is a serious question about kidney disease and the diagnosis will affect treatment management or prognosis, a kidney biopsy can be obtained. Occasionally, an invasive radiology procedure requiring contrast dye is necessary but these too are being replaced by the CT scan.
Following up
It is not uncommon that a source for the bleeding cannot be found even after an extensive workup. It is important, especially if there are risk factors for cancer, to be monitored and periodically reassessed. What may not be found on the first workup, may be on a later one.
