At-a-Glance Summary
- Hematuria means there are red blood cells in the urine.
- It is a sign, not a diagnosis by itself.
- The evaluation helps determine whether the bleeding may be glomerular, non-glomerular, or still unclear.
- Urinalysis, urine protein testing, blood pressure, blood tests, imaging, and sometimes cystoscopy help identify the cause.
- Blood in the urine should not be ignored, especially if it is visible, persistent, recurrent, or happens with pain, clots, fever, or trouble urinating.
Introduction
Seeing blood in the urine can be unsettling. Sometimes the urine looks pink, red, brown, or tea-colored. In other cases, blood is found only on a urine test. Either way, hematuria is an important finding that deserves medical evaluation.
Hematuria is not a disease by itself. It is a sign that red blood cells are entering the urine somewhere along the urinary tract. The source may be the kidneys, ureters, bladder, prostate, or urethra. One of the main goals of evaluation is to determine whether the bleeding appears more likely to be glomerular—coming from the kidney’s filtering system—or non-glomerular, meaning it is more likely coming from elsewhere in the urinary tract.
This distinction matters because a kidney stone, a urinary tract infection, and a glomerular disease may all cause hematuria, but they do not affect the body in the same way and they are not evaluated the same way.
What Hematuria Is
Doctors usually describe hematuria in two ways.
Gross Hematuria
Gross hematuria means there is enough blood in the urine for you to see it.
Microscopic Hematuria
Microscopic hematuria means red blood cells are present in the urine but can only be detected with laboratory testing.
Both types matter. Even when there is no pain, hematuria should not be ignored.
It is also important to remember that not all red or brown urine is true hematuria. Some foods, medicines, or pigments can change urine color. Testing helps confirm whether red blood cells are actually present.
What the Color of Urine May Suggest
Urine color alone cannot diagnose the cause, but it can offer clues.
- Bright red or pink urine may be more consistent with bleeding from the lower urinary tract.
- Brown, tea-colored, or cola-colored urine may suggest a glomerular source.
That darker color may occur because blood has been in the urine longer or because the bleeding is related to injury at the level of the kidney’s filtering units. Still, color alone is not enough to determine the source.
How the Kidneys Can Cause Hematuria
Inside the kidneys are millions of tiny filtering units called nephrons. Each nephron contains a glomerulus, a small cluster of blood vessels that helps filter the blood.
The glomerular filtration barrier is made of structures that normally prevent blood cells and large proteins from passing into the urine. When that barrier becomes inflamed, injured, or scarred, red blood cells and protein can leak into the urine.
This is why some forms of hematuria are discussed as glomerular hematuria. In these cases, hematuria may occur together with proteinuria, albuminuria, high blood pressure, swelling, or abnormal kidney function.
Symptoms That Can Help Point Toward the Cause
Hematuria may happen by itself or with other symptoms. These patterns can help doctors decide which causes are more likely.
Burning, Frequency, or Urgency
Burning with urination, urinary frequency, or urgency may be more compatible with infection, irritation, or another lower urinary tract problem.
Flank Pain or Lower Back Pain
Pain in the side or lower back may suggest a kidney stone, obstruction, or another upper urinary tract problem.
Swelling, High Blood Pressure, or Foamy Urine
Swelling, elevated blood pressure, or foamy urine can be more suggestive of a kidney or glomerular cause, especially when hematuria is persistent or recurrent.
Blood Clots or Trouble Urinating
Blood clots in the urine or difficulty urinating deserve prompt medical evaluation because they may suggest heavier bleeding or blockage.
Painless Visible Hematuria
Painless visible hematuria deserves timely medical evaluation because it can occasionally be linked to more serious urinary tract conditions.
Urologic vs. Nephrologic Causes of Hematuria
Doctors often organize the causes of hematuria into two broad categories: non-glomerular/urologic causes and glomerular/nephrologic causes.
Common Non-Glomerular or Urologic Causes
Urinary Tract Infection
A urinary tract infection can inflame the lining of the urinary tract and lead to hematuria. It often occurs with burning, urgency, frequency, or lower abdominal discomfort.
Kidney Stones
Kidney stones can scrape or irritate the urinary tract as they move. This may cause visible blood in the urine, often with severe pain in the side, back, lower abdomen, or groin.
Enlarged Prostate
In men, an enlarged prostate can affect urine flow and may be associated with hematuria. A weak stream, hesitancy, or incomplete emptying may also be present.
Bladder Tumors
Bladder tumors are part of the lower urinary tract differential and can present with hematuria, sometimes without pain.
Kidney Masses
Kidney masses can also cause hematuria, but the overall evaluation depends on the rest of the clinical picture and imaging findings.
Trauma
An injury to the back, abdomen, or pelvis can cause bleeding somewhere in the urinary tract.
Medicines
Some medicines, especially blood thinners, may be relevant during evaluation. Even so, hematuria should not automatically be blamed on medication alone.
Vigorous Exercise
Strenuous exercise can sometimes cause temporary hematuria. Even so, visible blood in the urine, persistent hematuria, or recurrent episodes still deserve medical evaluation.
Common Glomerular or Nephrologic Causes
Glomerulonephritis
Glomerulonephritis is a group of diseases that inflame and damage the glomeruli. When the filtering barrier is disrupted, red blood cells and protein may leak into the urine.
IgA Nephropathy
IgA nephropathy is a kidney disease in which immune deposits build up in the glomeruli and trigger inflammation. Hematuria is a common sign, and proteinuria can suggest more significant kidney involvement.
Other Glomerular Diseases
Other immune-mediated or inherited kidney diseases can also cause hematuria. In some cases, patients may also have:
- foamy urine
- swelling
- rising serum creatinine
- high blood pressure
Why Protein in the Urine Matters
Protein in the urine is not just an extra lab detail. When hematuria and proteinuria or albuminuria are present together, a glomerular source becomes more likely, especially if the hematuria is persistent.
That combination raises more concern for kidney disease than hematuria alone. It may prompt further evaluation by a nephrologist, especially when it occurs together with:
- high blood pressure
- swelling
- reduced kidney function
- persistent or recurrent hematuria
Why Blood Pressure and Kidney Function Matter
Blood pressure is an important part of the workup when hematuria is found.
High blood pressure can be:
- a clue that kidney disease may be present
- a factor that can worsen kidney damage over time
Doctors may also check serum creatinine and estimated glomerular filtration rate (eGFR) to better understand how well the kidneys are working.
What Doctors Are Trying to Determine
When hematuria is evaluated, doctors are usually trying to answer a few key questions:
- Is the bleeding more likely coming from the kidney’s filtering system or from somewhere else in the urinary tract?
- Is there protein in the urine, making a glomerular source more likely?
- Are there signs of infection, stones, blockage, structural problems, or kidney disease?
Tests Doctors Use for Hematuria
Seeing blood in the urine can be unsettling, but the evaluation is usually done step by step.
Urinalysis
Urinalysis is one of the first and most useful tests in the evaluation of hematuria. It can confirm that red blood cells are present and may also show protein, bacteria, crystals, or other abnormalities.
A urine sample is often reviewed in several ways:
- visual inspection
- dipstick testing
- microscopic examination
Microscopy can provide especially important clues. In some cases, clinicians look for dysmorphic red blood cells or acanthocytes, which may suggest that the bleeding is coming from the kidney’s filtering system rather than from the bladder or another lower urinary tract source.
If present, red blood cell casts are another clue that bleeding may be coming from the kidney.
Urine Protein Testing
Your clinician may also order a urine albumin-to-creatinine ratio (ACR) or another urine protein test. This helps determine whether blood is appearing in the urine together with protein.
Blood Tests
Blood tests can help evaluate kidney function and look for other clues. These may include serum creatinine, eGFR, blood counts, and tests guided by your symptoms and medical history.
Imaging Studies
Ultrasound, CT scan, or MRI may be used to look for stones, masses, obstruction, or structural abnormalities. These tests are chosen based on factors such as age, symptoms, risk factors, and whether the suspected source seems more likely to be in the upper or lower urinary tract.
Cystoscopy
Cystoscopy is usually performed by a urologist. A thin camera is passed through the urethra to examine the urethra and bladder more closely. This test may be recommended when the lower urinary tract needs a more direct evaluation.
Kidney Biopsy in Selected Cases
A kidney biopsy is not routine for every person with hematuria. However, it may be considered in selected cases when hematuria is persistent and is accompanied by significant proteinuria, abnormal kidney function, or other findings that raise concern for glomerular disease.
Important Safety Advice
Do not start or increase pain medicines on your own without medical guidance, especially if kidney disease is suspected.
This is particularly important with NSAIDs, such as ibuprofen or naproxen, because in some situations they can worsen kidney injury, especially with dehydration, low blood pressure, repeated use, or underlying kidney disease.
When to Seek Medical Care
Any visible blood in the urine should be discussed with a healthcare professional. Microscopic hematuria also deserves follow-up, especially if it persists.
A single episode matters, but persistent or recurrent hematuria increases the need for full evaluation.
Seek urgent care right away if hematuria happens together with:
- severe flank or abdominal pain
- fever or chills
- trouble urinating
- blood clots in the urine
- dizziness, weakness, or fainting
- vomiting or dehydration
- recent significant trauma
What to Expect at Your Appointment
During your visit, your doctor for kidney disease may ask about:
- when the bleeding started
- whether the urine looked pink, red, brown, or tea-colored
- whether you had pain, burning, urgency, clots, fever, or swelling
- whether this has happened before
- any recent exercise
- any new medicines, especially blood thinners
- your blood pressure history
- any known kidney problems
These details help guide the next steps in testing.
Final Thoughts
Hematuria may come from the urinary tract or from the kidney’s filtering system. The evaluation is designed to clarify that difference and identify the cause safely.
Urine testing, protein assessment, blood pressure, kidney function tests, imaging, and sometimes cystoscopy help doctors determine whether the source is more likely glomerular, non-glomerular, or still uncertain. Early evaluation matters because the right diagnosis guides the right treatment.
FAQs
Is blood in urine always serious?
Not always, but it should never be ignored. Hematuria can be caused by infections, stones, exercise, kidney disease, or more serious urinary tract conditions.
Can blood in urine come from the kidneys?
Yes. Hematuria can come from the kidneys, especially when the glomerular filtration barrier is inflamed or damaged.
What tests are done for hematuria?
Doctors may use urinalysis, urine protein testing, blood tests such as serum creatinine and eGFR, imaging studies, and sometimes cystoscopy or kidney biopsy.
When should I seek urgent care for hematuria?
Seek urgent care if blood in the urine happens with severe pain, fever, trouble urinating, clots, weakness, fainting, vomiting, dehydration, or after a significant injury.
What does blood and protein in urine mean?
When blood and protein are found together in the urine, a glomerular source becomes more likely, especially if the hematuria is persistent. This may suggest kidney disease and may require nephrology evaluation.