Blood in the Urine – Understanding Your Urine Test Results

Abschnittsredakteur: Christopher McCudden, Ph.D., DABCC, FADLM, FCACB
November 12, 2026

Blut im Urin, called hematuria, is a common urinalysis finding and is usually not caused by a serious problem. It can appear in two places on a report. The dipstick grades blood from trace to large, and the microscope counts red blood cells, as in “RBC 5-10/hpf.”

This article explains what a positive blood result on a urine test means and why the dipstick and the red blood cell count can disagree. It also describes the common causes of blood in the urine and how doctors decide which results need further tests.

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What do urine tests for blood measure?

Urine tests for blood look for rote Blutkörperchen that have entered the urine somewhere between the kidneys and the outside of the body. Two parts of a urinalysis check for blood, and they work differently.

Dipstick blood. A chemical pad on the dipstick changes color when it touches hemoglobin, the iron-containing protein inside red blood cells. The result is reported as a grade ranging from negative to large.
Red blood cells on microscopy. A technologist or an automated analyzer counts the actual red blood cells in the urine. The result is reported per high-power field (HPF), the circle of urine seen through the microscope at one time.

Blood that turns urine pink, red, or cola-colored is called visible, or gross, hematuria. Blood that can only be found by testing is called microscopic hematuria.

Why the dipstick and the red blood cell count can disagree

A positive dipstick for blood and a normal red blood cell count on the same urinalysis is a common and confusing combination. It happens because the dipstick reacts to hemoglobin, not to whole cells, and the two findings mean different things.

Red blood cells broke open in the sample. Red blood cells burst in very dilute or alkaline urine, or in a sample left too long before testing. The hemoglobin they release still turns the dipstick positive, but no intact cells are left to count.
Free hemoglobin from the blood. Some conditions break down red blood cells inside the blood vessels, and the released hemoglobin passes into the urine.
Myoglobin from muscle. Myoglobin is a protein similar to hemoglobin that is released when muscle is damaged, for example, after very intense exercise or an injury. It also turns the dipstick positive.

The opposite pattern also happens. Large doses of vitamin C can make the dipstick read negative even when red blood cells are present. For these reasons, guidelines from the American Urological Association (AUA/SUFU, 2020, amended 2025) say blood in the urine should not be diagnosed from a dipstick alone. A positive dipstick should prompt a microscopic examination, and the red blood cell count guides the next steps.

How is a urine test for blood performed?

A urine test for blood uses an ordinary clean-catch, midstream urine sample collected in a sterile cup. Because menstrual blood and blood from a recent procedure can enter the sample, the test is often timed to avoid them. If the first result may have been affected by a period, hard exercise, or contamination, a repeat sample is usually collected a few days later.

What do urine blood results mean?

Urine blood results are read by looking at the dipstick grade and the red blood cell count together.

Dipstick negative. No hemoglobin was detected, which is normal.
Dipstick trace or small. A small amount of hemoglobin was detected, and the microscope result shows whether red blood cells are really present.
Dipstick moderate or large. A larger amount was detected, which usually indicates red blood cells but can also indicate free hemoglobin or myoglobin.
RBC 0 to 2 per hpf. A few red blood cells are normal, and many laboratories report this as normal.
RBC 3 or more per hpf. The AUA/SUFU guideline defines this as microscopic hematuria when it is found on a properly collected sample.
Many RBCs or “too numerous to count.” So many red blood cells are present that they cannot be counted, which is common with visible blood.
Dysmorphic red blood cells or red blood cell casts. Misshapen red blood cells, or red blood cell casts, suggest the blood is coming from the kidney’s filtering units.

What can cause blood in the urine?

Blood in the urine has many possible causes, and most are not serious. Common and usually harmless causes include:

Menstruation. Menstrual blood can easily enter a urine sample.
Vigorous exercise. Long-distance running and other hard exercise can cause blood in the urine that clears within a few days.
A recent procedure. A urinary catheter or a procedure on the bladder or prostate can cause temporary bleeding.

Other causes of blood in the urine need a closer look:

Infektion. A bladder or kidney infection often causes red and white blood cells in the urine, usually with symptoms such as burning.
Nierensteine. Stones can scrape the lining of the urinary tract and often cause pain in the side or back.
Kidney conditions. Some diseases of the kidney filters, such as IgA-Nephropathie, cause blood in the urine, often with protein and sometimes with red blood cell casts.
Eine vergrößerte Prostata. In men, prostate enlargement can cause bleeding from small blood vessels.

Blood-thinning medicines do not, on their own, explain blood in the urine. People taking them are usually checked in the same way as everyone else.

When is blood in the urine investigated further?

In adults, persistent blood in the urine is sometimes investigated to ensure there is no problem in the kidney or bladder, including a tumor. This is a careful step, not a sign that cancer is expected. In studies of adults evaluated for microscopic hematuria, about 2 to 4 in 100 had bladder cancer, while the other 96 to 98 did not.

Under the AUA/SUFU guideline, the decision depends mainly on your age and smoking history. It also depends on how much blood is present and whether it keeps coming back on repeat tests.

People at the lowest risk usually need only a repeat urinalysis. Others may have an ultrasound or CT scan of the kidneys and a cystoscopy, a look inside the bladder with a thin camera. A Urinzytologie test, which looks for abnormal cells in the urine, is sometimes added in selected situations. Visible blood is more likely to be investigated than microscopic blood.

What happens after a positive urine test for blood?

What happens after a positive urine test for blood depends on the red blood cell count, your symptoms, and the other results on the urinalysis. A microscopic examination or a repeat urinalysis usually follows a positive dipstick. A Urinkultur may be done if infection is possible, and blood tests of kidney function or a urine albumin test may be added if protein or casts are present. Your doctor may refer you to a urologist for bladder and kidney problems, or to a nephrologist for problems with the kidney filters.

Fragen an Ihren Arzt

Was the blood on my urine test seen on the dipstick, under the microscope, or both?
How many red blood cells per high-power field were seen?
Could my period, exercise, or a recent procedure explain this result?
Should the test be repeated, and when is the best time to collect the next sample?
Could an infection or a kidney stone be causing the blood?
Did my urinalysis also show protein, red blood cell casts, or misshapen red blood cells?
Based on my age and smoking history, what is my risk category?
Do I need imaging or a cystoscopy, and why?
Would a urine cytology test be helpful in my situation?
Should I see a urologist or a nephrologist?

Blut im Urin – Ihre Urintestergebnisse verstehen