Red Blood Cell Microhematocrit (Micro-Hematocrit)
This test measures the proportion of red blood cells in a small sample of your blood, often done via capillary tube centrifugation. It helps assess red blood cell volume and can indicate conditions like anemia or polycythemia.
["Micro-Hematocrit helps diagnose blood-related conditions by checking red blood cell density in a simple, quick test."]
Key facts at a glance
- LOINC
- 68902-6
- Short code
- RBC ?Tm # UrnS Micro
- Synonyms
- RBC ?Tm # UrnS Micro
- Category
- chemistry
- Sample
- urine
- Container
- Sterile urine container
- Units
- N/A
- Ref low
- 4.2
- Ref high
- 5.9
- Critical range
- 2 N/A – 7 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- microscopy-light
- CPT
- 85041
- SNOMED
- 900000000000003001
- 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 Is This Test Done?
Your healthcare provider may order a micro-hematocrit test if you have symptoms like fatigue, shortness of breath, or unusual paleness. It’s also used to monitor blood disorders, hydration status, or during pregnancy to check for anemia or other blood-related issues.
How Is the Test Performed?
A small blood sample is taken from your finger or vein. The blood is placed in a thin capillary tube, which is then spun in a micro-hematocrit centrifuge. The layers of blood components separate, allowing the hematocrit percentage to be read.
What Does the Result Mean?
The result shows the percentage of red blood cells in your blood. Lower than expected levels may suggest anemia, while higher levels could indicate conditions like dehydration or polycythemia. Your provider will interpret results in the context of your symptoms and overall health.
Common Conditions Affecting Results
Micro-hematocrit results can be affected by dehydration, blood loss, or certain medications. Chronic conditions like kidney disease or heart failure may also influence red blood cell volume.
Reference range
Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Micro-hematocrit is a quick and reliable way to assess red blood cell concentration. It supports diagnosis of anemia, dehydration, or polycythemia and helps monitor treatment effectiveness for blood disorders.
Short name
Micro-Hematocrit
Frequently asked questions
What causes a low micro-hematocrit reading?
What causes a high micro-hematocrit reading?
Is this test painful?
Sources
- 1
- 2Lab Tests OnlineSource
- 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 17, 2026. · Read our editorial policy