Urine RBC (Red Blood Cells) -- Causes and Interpretation
It can be surprising to notice your urine is pink, red, or brown. When red blood cells (RBCs) end up in your urine, it can cause a change in its color. While having blood in your urine can be harmless, more serious conditions can cause this symptom. Healthcare providers can test your urine to screen for these more serious conditions and diagnose a possible cause.
Keep reading to learn more about what causes blood in your urine and how to get the correct tests — and answers — to keep you healthy.
What Are Urine RBCs?
Your blood contains three different types of cells. They are so small that you need a microscope to see them. RBCs are found in your blood and are what give your blood its red color.
You can have a small number of RBCs in your urine, but the color will still look yellow. However, if there are more RBCs, you may see blood, or your urine may change to pink, red, or brown. Depending on the cause of your urine RBCs, you may or may not have any other symptoms.
Sometimes you may have urine RBCs for a short time, and then they go away on their own. This is usually a reassuring sign, meaning there isn’t a problem to diagnose or treat.
How Do RBCs Get Into Your Urine?
Your urinary system filters your blood and removes wastes through urine. The urinary system is made up of the:
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Bladder
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Kidneys
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Urethra
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Ureter
RBCs can get into your urine from any of these parts. If you have an infection, such as a urinary tract infection (UTI), an injury or trauma (as with a kidney stone), or an abnormal growth (caused by cancer) in any of these parts, RBCs may pass into your urine. Tiny injuries or breaks in your blood vessels that are so small you need a microscope to see them are like open doors that allow RBCs to leak into your urine.
How Do You Know If You Have Urine RBCs?
Several types of laboratory tests can tell you whether or not you have RBCS in your urine. You can take these tests:
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At home
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At a laboratory
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At a healthcare center or a healthcare provider's office
The first test is called a dipstick test. Dipsticks are thin strips of plastic or paper with patches of chemicals. The chemicals change colors if you have too much of certain substances (like RBCs, protein, or glucose) in your pee. A dipstick test does not count the number of RBCs, but it indicates whether there are any RBCs present. The results of a dipstick test can determine whether you need more testing.
The second type of urine test is called a urine culture test. A urine culture test is usually the follow-up test for abnormal urine dipstick tests. This type of test is used to diagnose UTIs.
The urine culture test needs to be collected carefully so that no other dirt, germs, or RBCs from other parts of the body, such as the penis or vagina, get into your sample. This is why it is also referred to as a clean-catch urine sample. Your healthcare provider or laboratory will give you a specimen cup, sterile wipes, and specific instructions for collecting your urine sample.
The laboratory will look at your urine sample with a microscope. If you have a UTI, your urine culture sample can also be tested to find out which antibiotic will best treat your UTI. If the lab finds red or white blood cells, bacteria, yeast, or other substances, the results might be listed as “few,” “moderate,” or “many.”
What Are Normal and Abnormal Results for a Urine RBC Test?
A normal result is three red blood cells per high-power field (RBC/HPF) or less when the sample is examined under a microscope. Having more than three RBCs is an abnormal result and should be followed up with further testing, such as a urine culture test.
It is common for dipstick tests to yield false or incorrect results, either positive or negative. That is why it is a good idea to follow up with further testing if:
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You have a positive result (more than 3RBC/HPF)
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You had a negative test (less than 3 RBC/HPF), but continue to have other symptoms such as pain when you pee, having to pee more often, lower back pain, a fever, or a change in the color of your urine
Urine RBCs, UTIs, and Sexually Transmitted Infections (STIs)
A urinary tract infection (UTI) is an infection in either your bladder, kidneys, urethra (where your pee exits your body), or your ureter (the tube connecting your bladder and urethra). Bacteria cause a UTI. The most common form of UTI is a bladder infection.
UTIs are not sexually transmitted, but having sex can make it easier to get a UTI.
Are you wondering about the cause of your symptoms: UTI vs STI? Gonorrhea, chlamydia, and trichomonas can all cause urine RBCs. If you have other STI symptoms, it is important not to ignore them.
Other Causes of Urine RBCs
Besides UTIs, there are many other possible causes of urine RBCs. Some conditions affecting the kidneys and resulting in RBCs leaking into the urine are:
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Kidney stones
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Kidney infections
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Kidney disease
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Kidney injury, as might happen in a contact sport like football or hockey
The other causes of urine RBCs are:
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Sickle cell disease
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Intense exercise, such as running a marathon
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Enlarged prostate
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Cancer, most often seen in adults older than 35
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Certain medicines, such as blood thinners, nonsteroidal anti-inflammatory drugs (NSAIDs), and some antibiotics
If you notice blood in your urine, schedule a visit with a healthcare provider so they can diagnose the cause.
Telehealth With Everlywell
Everlywell makes urine lab testing easy and convenient with at-home collection and digital results in days. You can also review your symptoms and lab results with an Everlywell healthcare provider. At your virtual care appointment, you can:
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Figure out what your symptoms could mean
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Learn which urine tests you need
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Get treatment for some conditions causing urine RBCs, such as STIs and UTIs
The most effective way to get rid of a UTI or an STI is to treat it with medicines called antibiotics. Ignoring your symptoms and any changes in your urine color could put your health at risk. Testing for urine RBCs can be a quick and convenient way to screen for more serious conditions.