Several conditions can cause red blood cells to appear in your urine, from
strenuous exercise to bleeding disorders.
Overview
Whether
or not you see pink in the toilet, you may have red blood cells (RPCs) in your
urine. The urine contains red blood cells called hematuria.
There
are two types of hematuria:
- Gross hematuria
means that blood is visible in the urine.
- Microscopic
hematuria involves red blood cells that can only be seen under a
microscope.
Red
blood cells are usually not found in the urine. Their presence is usually a
sign of an underlying health problem, such as infection or irritation of the
tissues of the urinary tract.
How are red blood cells detected in the urine?
Doctors
usually test for red blood cells during urinalysis. For this test, a person is
provided with a urine sample for the test.
Ideally,
this urine sample will be a clean capture sample. Providing a clean capture
sample involves cleaning your genital area and allowing a small amount of urine
to enter the toilet before putting the remaining urine into the sample cup.
This helps ensure that the urine sample is free of any contaminants.
The
sample is then sent to a laboratory for testing. Sometimes, doctors use
dipsticks to quickly test for red blood cells in a urine sample before sending
the sample to a lab.
The
dipstick looks like a piece of paper, but it contains chemicals that change the
color of the paper if it comes into contact with red blood cells. This does not
give an accurate measurement, but it can help narrow the diagnostic range or
rule out certain conditions.
What is
the normal range of red blood cells?
Red
blood cells are usually absent in the urine and therefore do not have a normal
range.
However,
if you are in your period of menstruation when you provide a urine sample, you
may have red blood cells in your urine. This doesn't have to worry, but be sure
to tell your doctor before providing a sample of what you are menstruating.
What causes red blood cells to appear in the urine?
Some of
the causes of high red blood cells in the urine may be acute. This means that
they are temporary conditions that last only a short time.
Some
acute causes of red blood cells in the urine include:
- Infection. Infections in the
urethra, bladder, kidneys, or prostate can cause inflammation and
irritation, leading to the appearance of red blood cells in the urine.
- Sexual activity. Recent sexual
activity can irritate tissues around the urinary tract.
- Strenuous exercise. Recent
strenuous activity can also inflame the tissues of the urinary tract.
- Kidney stones or bladder
stones. Minerals in the urine crystallize and cause stones to
attach to the kidneys or bladder walls. They do not cause you any pain
unless they loosen and pass through the urinary tract, which is very
painful. Irritation of stones can cause blood in the urine, whether small
or massive.
Some
chronic (long-term) disorders that can cause the appearance of red blood cells
in the urine to include:
- Hemophilia. This is a bleeding
disorder that makes it more difficult for a person's blood to clot. This
leads to easy bleeding.
- Polycystic kidney disease. This condition
involves cysts growing on the kidneys.
- Sickle cell disease. This disease can
lead to the irregular shape of red blood cells.
- Viral hepatitis. Viral infections
can inflame the liver and cause blood in the urine.
- Bladder cancer or kidney cancer. Both of these
conditions sometimes cause red blood cells to appear in the urine.
Some
drugs can also cause the appearance of red blood cells in the urine. Examples
include:
- Blood thinner
- Aspirin
- Antibiotics
Before
providing a urine sample, be sure to tell your doctor about all medications you
are taking, including any over-the-counter (OTC) medications.
What is the next step after finding red blood cells in the
urine?
If your
urine sample tests positive for red blood cells, your doctor may check for
other test results first. For example, if you also have certain bacteria or
white blood cells in your urine, you may be infected.
Your
doctor may also ask for blood tests, such as a complete blood count or a basic
metabolic test, to better understand how well your kidneys are working.
Depending
on your other symptoms and medical history, you may need to have more invasive
tests. For example, a cystoscopy involves inserting a small camera into your
urethra to better visualize your bladder.
Your
doctor may also perform a tissue biopsy of your bladder or kidneys to check for
any signs of cancer. This involves taking small tissue samples from these
organs and observing them under a microscope.
Conclusion
Several
conditions can cause red blood cells to appear in your urine, from strenuous
exercise to bleeding disorders. Be sure to tell your doctor about any other
symptoms you have and any prescription or over-the-counter medications you
take.
If your
urine sample tests positive for red blood cells, your doctor may do some
additional tests to help determine the underlying cause.