Understanding Your Laboratory Test: A Complete Patient Guide to Diagnosis and Screening
A microscopic examination of urine sediment to detect and count bacteria, helping diagnose urinary tract infections.
{"This test examines urine under a microscope to find bacteria","It helps diagnose bladder and kidney infections","Results are reported as bacteria seen per area of view","A positive result usually means a urinary tract infection (UTI)","Results are combined with other urinalysis findings for diagnosis"}
Key facts at a glance
- LOINC
- 105051-7
- Short code
- URBACT
- Synonyms
- Bacteria UrnS Micro-#/area
- Category
- chemistry
- Sample
- urine
- Container
- Sterile, leak-proof urine collection container or vacuum urine transport tube (yellow-top or gray-top borosilicate tube); preferably a sterile container without preservatives for routine urinalysis
- Units
- N/A
- Ref low
- 0
- Ref high
- 5
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- microscopy
- CPT
- 81015
- SNOMED
- 167776002
- Specimen volume
- 10-50 mL of urine; minimum 5 mL recommended for adequate sediment analysis
- Stability
- Analysis should be performed within 1-2 hours of collection at room temperature; refrigerated (2-8°C) specimens stable for up to 24 hours; bacterial overgrowth may occur with prolonged storage at room temperature
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 1–4 hours
- Order
- routine
What is this test, and what exactly does it measure in my body?
The Bacteria in Urine Sediment by Microscopy test is a laboratory examination that looks at a sample of your urine under a microscope. The test identifies and counts bacteria present in the urine sediment—the solid material that settles at the bottom when urine is spun in a centrifuge. This test is part of a complete urinalysis and helps healthcare providers determine if you have a urinary tract infection (UTI).
How is this test performed, and what can I expect during the procedure?
A urine sample is collected, usually via a clean-catch midstream method to avoid contamination. The sample is placed in a centrifuge to separate the liquid from the solid particles (sediment). The sediment is then examined under a microscope by a lab technician, who counts the number of bacteria seen in each field of view. Results are typically reported as few, moderate, or many bacteria per high-power field (HPF).
Why might my doctor recommend this test, and what conditions can it help detect?
Your doctor may order this test if you have symptoms of a urinary tract infection, such as pain or burning during urination, frequent urge to urinate, cloudy or foul-smelling urine, or pelvic pain. It is also used to monitor treatment effectiveness for UTIs and to check for recurrent infections, especially in people with diabetes, pregnant women, or those with recurrent urinary problems.
How should I prepare for this test, including food, drink, and medication guidelines?
No special preparation is usually required for this test. However, it is best to collect a first-morning urine sample when urine is most concentrated. Make sure to follow the instructions provided by your healthcare provider for proper urine collection to avoid contamination. Inform your doctor about any medications or supplements you are taking, as some may affect results.
Reference range
None to rare (0-5 per HPF); clinical significance depends on clinical context, presence of symptoms, and concurrent findings such as pyuria or bacteriuria on cultureN/A
No special preparation required; midstream clean-catch urine specimen preferred to minimize contamination from external genitalia flora; patients should be instructed on proper collection technique
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Presence of bacteria in urine sediment, especially in significant numbers, typically indicates a urinary tract infection (UTI). The most common bacteria causing UTIs include Escherichia coli (E. coli), Klebsiella, Proteus, and Enterococcus. The test helps differentiate between contamination (low numbers of mixed bacteria) and true infection (significant numbers of a single type of bacteria). In combination with other urinalysis findings—such as presence of white blood cells (pyuria), nitrites, or leukocyte esterase—the test helps confirm diagnosis and guide treatment decisions. In some cases, a urine culture may be ordered to identify the specific bacteria and determine which antibiotics will be most effective.
Frequently asked questions
Does the presence of bacteria always mean I have an infection?
How long does it take to get results?
What do the results mean?
Do I need to do anything special after the test?
Sources
- 1MedlinePlus - UrinalysisSource
- 2Mayo Clinic - UrinalysisSource
- 3
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.
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