What does it measure?
This part of urinalysis examines urine sediment under a microscope or an automated cell system. It differs from the dipstick blood reaction, which can also detect free blood or muscle pigments. The lab reports a cell count using its own method and units.
Before the test
- Sample
- Collect urine in the laboratory’s container, following its clean-catch instructions.
- Mention
- Tell the clinician about menstruation and medicines that may affect bleeding.
What can the result mean?
More red cells than expected can come from the kidneys or another part of the urinary tract. Infection, stones, exercise, and other causes are possible. A count alone cannot locate the source or determine how serious it is. [1]
When is it useful, and how is it read?
Read this in a properly collected sample, with pain, infection symptoms, stone history, and whether the finding persists. Protein or red-cell casts may point the clinician toward a kidney source, while other causes need a different assessment. [1]
What can affect it?
Menstrual blood, a recent catheter, and vigorous exercise can complicate the picture. Dilute or old samples may allow cells to break apart, so proper collection and timing matter. [1]
Myth: «Microscopic blood tells us where bleeding started»
A red-cell count shows cells are present, but does not locate their source. Symptoms, other urine findings, and sometimes further assessment are needed to understand where they came from. [1]
Questions you might have
What does “per high-power field” mean?
It describes how many red cells the laboratory saw in a small microscope viewing area. [1]
Does finding red cells show where the bleeding started?
No. Symptoms and other tests help distinguish kidney, bladder, and other possible sources. [1]
What comes next?
Your clinician may repeat a properly collected sample and review protein, kidney function, symptoms, and personal risk factors. Persistent confirmed red cells need a clear follow-up plan even when you feel well. [1]
Is this confirmed on a well-collected sample, and what would guide further investigation?
The reference interval and units on your report are part of understanding your result. Understand units, reference intervals, and treatment targets.
Sources & references
Medical references & original research
Books we consulted
References that informed our explanations of the test and its context.
- Pagana KD, Pagana TJ, Pagana TN. Mosby’s Diagnostic and Laboratory Test Reference. 14th ed. Elsevier; 2019.
Practical-section sources accessed: .
For general health education. Interpreting your result and deciding on tests or treatment requires your health context and a qualified clinician.
