Red Blood Cell (RBC) Count by Microscopic Examination
This test measures the number of red blood cells in your blood using a microscope. It helps assess your body’s ability to carry oxygen and detect conditions like anemia or polycythemia.
["This test checks your RBC levels to identify potential blood disorders or health concerns."]
Key facts at a glance
- LOINC
- 23859-2
- Short code
- RBC # Spec Micro
- Synonyms
- RBC # Spec Micro
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- 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
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test if you have symptoms like fatigue, pale skin, shortness of breath, or unusual bruising. It’s also used to monitor conditions like anemia, blood loss, or certain blood disorders. Sometimes, it’s part of routine blood checks or during pregnancy.
What Does a Low or High RBC Count Mean?
A low RBC count (anemia) may indicate iron deficiency, chronic illness, or blood loss. A high RBC count (polycythemia) could suggest dehydration, lung disease, or a genetic condition. Your provider will discuss results with you based on your symptoms and medical history.
How Is This Test Performed?
A small blood sample is drawn from a vein, usually in your arm. The sample is then examined under a microscope to count the RBCs. This is a quick and painless process.
What Are Common Results?
Results are typically reported as a count of RBCs per microliter (µL) of blood. While reference ranges vary by lab, your provider will compare your results to your specific baseline and overall health.
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.
◆Associated findings1
Short name
RBC Count (Microscopic)
Frequently asked questions
What causes a low RBC count?
What causes a high RBC count?
How often should I get this test?
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