Kidney & Urinary Health

Add us on Google

Blood in Urine Test Results: What RBC, Trace and Occult Blood Mean

A urine test that shows blood, trace blood, occult blood or red blood cells is common and often has a temporary cause. Learn how to read the two blood lines on a urinalysis, what counts as a high RBC result, and what happens next.

Published

October 23, 2026

Read time

11 min read

Medically reviewed by

Rhonda Collins, FNP-C

Share

Copy link

Summarize with AI

Blood on a urine test is common and often has a temporary cause, but it should be confirmed and, if it persists, followed up. A urinalysis can show blood in two different ways: a dipstick line for blood (sometimes labeled hemoglobin or occult blood) and a microscopic count of red blood cells (RBC) per high-power field ^[1][2]. The American Urological Association (AUA) defines microscopic hematuria as 3 or more red blood cells per high-power field on a single urine sample examined under a microscope ^[3].

Many healthy people have small amounts of blood in the urine that goes away on its own ^[4]. Infection, kidney stones, menstruation and hard exercise are common causes ^[4][5]. The same finding can also come from kidney disease or, less often, bladder or kidney cancer, which is why a positive result is repeated and, depending on your risk, evaluated ^[3][4][5].

Microscopic vs visible blood in urine

Hematuria means blood in the urine ^[4]. It comes in two forms:

• Microscopic hematuria. The urine looks normal, but a urine test finds blood ^[4][6]. This is what most people mean when a lab report shows trace blood, occult blood or red blood cells.
• Visible (gross) hematuria. Blood can be seen in the toilet or a cup, and the urine may look pink, red, or the color of tea or cola ^[4]. Even a small amount of blood can change the color ^[4].

Red or dark urine is not always blood. Some medicines, beets and other foods, and food coloring can change urine color ^[4][6]. That is one reason a urine test, not the color alone, answers the question.

The two blood lines on a urinalysis report

A routine urinalysis looks at urine three ways: its color and appearance, chemical tests on a dipstick, and a microscopic exam of the urine sediment ^[2]. Blood shows up in two of them, and they measure different things.

A positive dipstick needs a microscopic exam to confirm it. The National Kidney Foundation describes the dipstick as only a screening test whose results must be confirmed by looking at the urine under a microscope ^[4]. A summary of the AUA guideline for family physicians notes that at least 20% of positive dipstick tests for blood have no red blood cells on microscopy ^[5].

On Mito reports these lines map to urine red blood cells, which some labs call urine erythrocytes, and to the dipstick reading for occult blood.

What counts as a high RBC count in urine?

Three or more red blood cells per high-power field is the AUA’s definition of microscopic hematuria ^[3]. That definition applies to a single specimen examined under a microscope, not to a dipstick ^[3][5].

Lab reference ranges are set by each lab and can differ. MedlinePlus lists a common normal result as 4 RBC/HPF or less, while noting that ranges vary between labs ^[1]. A count of 3 or 4 can therefore sit inside a lab’s printed range and still meet the urology definition. Read the number against your own lab’s range, and treat a borderline result as a reason to repeat the test rather than a verdict.

Higher counts carry more weight. In the AUA’s 2020 risk system, the number of red cells on one test was one of the factors that set a person’s risk group, and a count above 25 RBC/HPF placed a person in the high-risk group on its own ^[5]. The guideline was amended in 2025 with a revised risk stratification system ^[8], so the exact cutoffs a clinician uses may differ from the 2020 version.

Trace or occult blood with no red blood cells

A dipstick that shows blood while the microscope finds few or no red cells is a common and confusing combination. It happens because the dipstick pad reacts to the peroxidase activity of hemoglobin, not to whole cells ^[7]. Several things can turn it positive:

• Free hemoglobin. Hemoglobin outside intact red cells still reacts with the pad ^[7].
• Myoglobin. Myoglobin, the oxygen-carrying protein in muscle, also triggers the pad ^[7]. Muscle breakdown releases myoglobin into the blood, where the kidneys filter it out ^[9]. Severe exertion, such as marathon running, is one listed cause ^[9]. Large amounts can make urine dark, red or cola-colored ^[9].
• Menstrual blood or other contamination. Blood from the vagina can end up in the sample and is a common cause of a positive result ^[5][6]. Other peroxidases, for example from semen or bacteria, can also affect the pad ^[7].
• Collection and handling. Tubes with preservatives and how the sample is handled before testing can change the result ^[7].

In this situation, the next step is a repeat, properly collected sample with a microscopic exam ^[4][5]. Dark urine with muscle pain, weakness or reduced urine output after intense exercise or an injury is different: it can be a sign of muscle breakdown and needs prompt medical care ^[9].

Temporary causes of blood in urine

Many positive results have a cause that passes:

• Hard exercise. The National Kidney Foundation lists heavy exercise among the causes of hematuria ^[4].
• Menstruation, including blood that contaminates a sample ^[4][5].
• A urinary tract infection. Infection is one of the most common causes of hematuria in adults ^[4].
• A recent procedure, such as a cystoscopy or a pelvic exam with a Pap smear ^[4].

The AUA guideline says that when blood is traced to a gynecologic or non-cancer urinary cause, the urinalysis should be repeated after that cause has resolved ^[3]. The family-physician summary adds that a repeat test after a treated urinary infection should be considered, because women later found to have urinary tract cancer are often first treated repeatedly for infections ^[5].

How to get a clean repeat result

• Use a clean-catch sample, which helps keep germs from the penis or vagina out of the sample ^[1].
• Test outside your period.
• Avoid collecting the sample right after unusually hard exercise.
• Ask for a microscopic exam, not a dipstick alone ^[4][5].

A single properly collected urinalysis is enough to define microscopic hematuria ^[3], so a repeat is about confirming the result and checking whether it persists, not about collecting many samples.

Causes worth checking

When blood persists or has no temporary explanation, the cause is usually in the kidneys or urinary tract. Commonly listed causes include ^[4][6]:

• Infection or inflammation of the bladder, urethra, prostate or kidneys.
• Kidney stones or stones elsewhere in the urinary tract.
• An enlarged prostate (benign prostatic hyperplasia).
• Kidney disease, including glomerular disease, where the kidney’s tiny filters are damaged, and polycystic kidney disease.
• Inherited conditions such as sickle cell disease, and bleeding disorders.
• Bladder or kidney cancer, and prostate cancer.

Cancer is the cause people worry about, and it is the reason guidelines take persistent blood seriously. Most people with microscopic blood do not have cancer, and microscopic hematuria carries a lower cancer risk than visible blood ^[5]. Risk is not the same for everyone, though. The National Kidney Foundation notes that unexplained blood that goes away is usually not a problem in people under 35, but that in people older than 35 it can be a sign of cancer even when it is temporary ^[4].

Who needs a full evaluation

The AUA guideline sorts people with microscopic hematuria into low, intermediate and high risk for urinary tract cancer and matches the evaluation to that risk, with shared decision-making ^[3][8]. The factors it uses are ^[3][5]:

• Age and sex, with risk rising with age.
• Smoking history, counted in pack-years.
• How many red cells are seen per high-power field.
• Whether the blood persists on a repeat test.
• Any past episode of visible blood.
• Other risk factors for urinary tract cancer, such as occupational exposure to benzene or aromatic amines, past pelvic radiation, past cyclophosphamide chemotherapy, or a long-term urinary catheter.

In the 2020 version, people at low risk could repeat the urinalysis within six months rather than go straight to a full evaluation, while people at intermediate or high risk were advised to have their bladder and upper urinary tract examined, usually by a urologist ^[5]. Taking blood thinners does not explain away microscopic blood: the summary notes that people on these medicines should still be evaluated ^[5].

Blood and protein in urine together

Blood and protein in the same urine sample point more toward the kidneys. The National Kidney Foundation states that protein in the urine together with hematuria usually means there is a problem with the kidneys ^[4]. Protein helps show where the blood may be coming from: a filter problem in the kidney rather than bleeding lower in the urinary tract ^[4].

That combination is checked with a kidney evaluation, not another dipstick. The standard pair is a urine albumin-to-creatinine ratio, which measures albumin leaking into the urine, and an eGFR, an estimate of kidney filtering calculated from blood creatinine ^[4][10]. Albumin in the urine can signal kidney disease even when eGFR is above 60, which many people read as normal ^[10]. For more on the protein side, see protein in the urine, what the urine albumin-to-creatinine ratio means, and what foamy urine can mean.

The Kidney Panel pairs the urine albumin-to-creatinine ratio and urine microalbumin with blood creatinine and a creatinine-based eGFR. It answers the follow-up question when a urinalysis shows both blood and protein: is albumin leaking, and how well are the kidneys filtering.

What happens next after blood shows up on a urine test

1. Confirm it. A positive dipstick is confirmed with a microscopic exam ^[4][5].
2. Look for a clear cause. Infection, menstruation, recent hard exercise, a stone or a recent procedure. If one is found, repeat the urinalysis once it has resolved ^[3].
3. Check the kidneys when protein, swelling or a rising creatinine is present. Urine protein, creatinine and eGFR help show whether the kidneys are the source ^[4].
4. Match follow-up to risk. If blood persists with no explanation, your age, smoking history, red cell count and any past visible blood decide whether a repeat test or a full urologic evaluation is the next step ^[3][5].

The Urinalysis, Routine Test includes the hemoglobin dipstick, urine protein and a microscopic exam of the urine sediment, so one repeat sample covers both blood lines and the protein reading.

When to get prompt care

Most microscopic blood can be followed up with a routine visit and a repeat test. Visible blood is different, and some symptoms need care right away.

Never ignore blood you can see in your urine ^[6]. Get checked promptly even if it stops on its own, because visible blood is more strongly linked with cancer than microscopic blood ^[5].

Contact a clinician right away if blood in the urine comes with any of these ^[4][6]:

• Blood clots in the urine, or a large amount of blood.
• Being unable to urinate.
• Fever, shaking chills, nausea or vomiting.
• Pain in the belly, side or back.

The National Kidney Foundation notes that large amounts of blood or clots can be an emergency, because clots can block urine flow and heavy bleeding can cause low blood pressure ^[4]. Dark or cola-colored urine with muscle pain, weakness or less urine than usual after intense exercise or an injury also needs prompt care ^[9].

References

1. MedlinePlus. RBC urine test. National Library of Medicine. Reviewed July 13, 2025.
2. MedlinePlus. Urinalysis. National Library of Medicine. Reviewed January 1, 2025.
3. Barocas DA, Boorjian SA, Alvarez RD, et al. Microhematuria: AUA/SUFU guideline. J Urol. 2020;204(4):778-786. PMID: 32698717
4. National Kidney Foundation. Hematuria (blood in the urine) in adults. Updated February 21, 2025.
5. Arnold MJ. Microscopic hematuria in adults: updated recommendations from the American Urological Association. Am Fam Physician. 2021;104(6):655-657.
6. MedlinePlus. Urine, bloody. National Library of Medicine.
7. Delanghe J, Speeckaert M, Delanghe S, Oyaert M. Pitfalls in the diagnosis of hematuria. Clin Chem Lab Med. 2023;61(8):1382-1387. PMID: 37079906
8. Barocas DA, Lotan Y, Matulewicz RS, et al. Updates to Microhematuria: AUA/SUFU Guideline (2025). J Urol. 2025;213(5):547-557. PMID: 40013563
9. MedlinePlus. Rhabdomyolysis. National Library of Medicine.
10. National Kidney Foundation. Albuminuria (proteinuria).

Frequently asked questions

What level of RBC in urine is concerning?

The American Urological Association defines microscopic hematuria as 3 or more red blood cells per high-power field (RBC/HPF) on a single properly collected urine sample examined under a microscope. Many lab reports list about 0 to 4 RBC/HPF as normal, so ranges vary by lab. Higher counts raise concern: in the 2020 version of the urology guideline, more than 25 RBC/HPF on one test placed a person in the highest risk group on its own. The count is read together with age, smoking history, whether the result persists and any past visible blood.

Should I be worried about red blood cells in urine?

It is rarely an emergency on its own, but it should not be ignored. Many healthy people have small amounts of blood in the urine that goes away, and common causes include infection, kidney stones, menstruation and hard exercise. Because the same finding can come from kidney disease or, less often, bladder or kidney cancer, a positive result should be confirmed with a repeat urinalysis and followed up when it persists or when you have risk factors.

What to do when RBC is high in urine?

Repeat the urinalysis on a properly collected clean-catch sample, away from your period and from unusually hard exercise, and with a microscopic exam rather than a dipstick alone. If an infection or other clear cause is found, repeat the test after it has resolved. If red blood cells are still present, or you are at higher risk because of age, smoking or past visible blood, the next step is an evaluation by your doctor or a urologist. Get care promptly for visible blood with clots, fever, side pain or trouble urinating.

What does trace blood in urine mean?

Trace blood means the dipstick pad for blood changed color slightly. The pad reacts to hemoglobin, so it can turn positive with intact red cells, free hemoglobin, myoglobin from muscle, or blood from menstruation. A trace result is a screening signal, not a diagnosis, and it needs a microscopic exam to see whether red blood cells are actually present.

Is occult blood in urine the same as blood in stool?

No. Occult means hidden, so occult blood in urine is blood you cannot see that a urine dipstick or microscope detects. A fecal occult blood test is a separate stool test used to look for bleeding in the digestive tract. The two results come from different samples and point to different parts of the body.