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Urine Microscopic Examination for Red Blood Cells (RBCs) and White Blood Cells (WBCs)

Published: August 9, 2026Updated: August 16, 2026

This test examines your urine under a microscope to check for the presence of red or white blood cells, which can indicate infections, bleeding, or other health issues.

Quick summary

["Microscopic urine analysis helps identify potential urinary tract or kidney problems early."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
28545-2
Short code
Mucous Threads #/area UrnS LPF
Synonyms
Mucous Threads #/area UrnS LPF
Category
chemistry
Sample
urine
Container
Sterile urine container
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
microscopy-light-lpf
Specimen volume
10 mL
Stability
Room temperature: 2h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
0
Lipemia max
0
Icterus max
0
TAT
4–24 hours
Order
routine

Why This Test Is Done

Your healthcare provider may order this test if you have symptoms like frequent urination, pain while urinating, blood in urine, fever, or unexplained weight changes. It’s also used to monitor conditions like kidney disease or urinary tract infections.

What to Expect Before the Test

No special preparation is needed. You’ll likely provide a midstream urine sample in a clean container. Avoid using urinary tract medications or certain hygiene products for 24 hours before testing if instructed.

What Happens During the Test

The sample is sent to a lab where it’s examined under a microscope. Technicians look for red or white blood cells, bacteria, or other abnormalities that may signal infection, inflammation, or kidney issues.

Possible Results and Their Meaning

If red or white blood cells are found, it may mean you have a urinary tract infection, kidney stones, or another condition affecting your urinary system. Your provider will discuss results with you and may recommend further testing or treatment.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance

Short name

Urine Microscopy

Frequently asked questions

What causes red or white blood cells in urine?
Red blood cells can appear due to urinary tract infections, kidney disease, bladder stones, or trauma to the urinary tract. White blood cells often signal infections (like UTIs) or inflammation. Other causes may include kidney disease, sexually transmitted infections, or certain medications.
What does it mean if my urine test shows no cells?
A negative result for red or white blood cells typically means your urinary system appears healthy, but it doesn’t rule out other conditions. Follow-up testing may still be needed if you have symptoms or risk factors for urinary issues.
Can I drink water before this test?
Yes, you can drink water as usual, but avoid excessive hydration that might dilute the sample. Follow any specific instructions your provider gives you, as some tests require a clean-catch midstream sample to avoid contamination.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy