Can You Have Blood in Your Urine and Not Know It?

The medical term defining the presence of blood in urine is hematuria. Several diseases and health conditions can cause blood in urine, which may or may not be visible. Even if it's a one-off, hematuria can be a sign of a serious health issue. Ignoring it won't make it go away, and it could be a sign of worsening conditions like kidney disease. While you might not know there is blood in your urine in some cases, it is best to seek medical assistance as soon as possible if you do notice any signs of blood in your urine. A urologist will analyze your urine and conduct urine tests and imaging tests to determine the cause of the problem and develop a treatment plan around the results.

Can You Have Blood in Your Urine and Not Know It?

You can have small amounts of blood in your urine and now know it because you can't see it. A test called a urinalysis can find a small amount of blood cells in your urine as well as other types of cells, chemicals, and substances.

The Types of Hematuria Explained

Gross Hematuria

If your blood appears pink or has red spots, it's "gross hematuria."

Microscopic Hematuria

If you don't notice any change in the color of your urine, it's because the amount of blood in it is so minuscule it's not visible to the naked eye. This condition is called "microscopic hematuria." Only lab tests can determine if you have microscopic hematuria.

What are the Causes of Hematuria?

There are several causes of gross or microscopic hematuria, most of which are severe conditions requiring immediate medical treatment.


One of the more common causes of hematuria is an infection of the kidneys, urinary tract, or bladder. Infections occur when bacteria migrate up the urethra and into the bladder and kidneys, causing sensations of pain, burning when urinating, and gross or microscopic hematuria. The good news is that a urologist can treat these types of infections with antibiotics, and you'll fully recover.

Bladder or Kidney Stones

Kidney or bladder stones are another common cause of gross or microscopic hematuria. These stones develop from minerals crystalizing in your urine. The stones can develop in the kidneys or bladder, causing significant pain and the onset of hematuria. Smaller stones will pass naturally, but larger ones may require treatment with medication to break them down or surgical removal.

Kidney Disease

Kidney disease is one of the less common reasons for hematuria. An inflamed or diseased kidney can cause the condition and may occur alone or alongside other conditions like diabetes.

Post-Streptococcal Glomerulonephritis

Children aged 6 to 10 may develop a condition called post-streptococcal glomerulonephritis, causing the onset of hematuria. This disorder usually develops a few weeks after a strep infection that goes untreated. Doctors can treat this disorder with antibiotics.

Benign Prostate Hyperplasia – Prostate Enlargement

Middle-aged men might develop an enlarged prostate gland known as Benign Prostate Hyperplasia (BPH). The prostate sits under the bladder and near the urethra. As the prostate swells, it exerts pressure on the urethra, preventing the bladder from completely emptying. As a result, the patient develops an infection, resulting in the onset of hematuria.


Some medications may cause health complications, including hematuria. Common drugs that can cause hematuria include the following:

  • Aspirin
  • Penicillin
  • Blood thinners like Warfarin and heparin
  • Cyclophosphamide


Finally, cancer of the kidneys, prostate, or bladder may result in the onset of hematuria. Typically, hematuria is a sign of advanced stages of cancer, and the patient may not notice the microscopic hematuria that occurs in the early stages of their condition.

Less Common Causes of Blood in Urine

Some causes of hematuria are less common, such as rare blood disorders like Alport syndrome, sickle cell anemia, and hemophilia. People that experience a significant impact on the kidneys may also experience the onset of hematuria.

When to See the Doctor

Since most of the causes of hematuria involve the presence or advancement of severe health conditions, you'll need to see a urologist ASAP if you notice any signs of blood in your urine. Microscopic hematuria is very difficult to detect, and you might not notice it until the color of your urine starts changing. However, if you see a slight pink tinge in your urine when it should be clear, consult with a urologist near you immediately.

Don't ignore the issue, even if it's only a small presence of blood in your urine. If you experience pain in your kidneys or frequent or painful urination, consult with a local urologist immediately. These symptoms might be indications you're dealing with microscopic hematuria.

If hematuria occurs alongside symptoms like vomiting, nausea, chills, fever, or pain in the side or abdomen, seek emergency medical assistance.


The attentive, compassionate physicians, providers, and staff at Adult Pediatric Urology & Urogynecology are committed to providing innovative, quality patient care in our state-of-the-art facility.

From screening and prevention to treatment and recovery, our health professionals will be there for you. Our team of dedicated physicians has been serving residents of Nebraska, Iowa, and South Dakota for more than 25 years.

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