Red Blood Cell Count, Qualitative
A red blood cell (RBC) count measures the number of red blood cells in a blood sample, which carry oxygen throughout the body. It is a standard part of a complete blood count used to evaluate anemia and other blood conditions.
["Your RBC count helps show whether you have a healthy number of oxygen-carrying red blood cells."]
Key facts at a glance
- LOINC
- 33668-5
- Short code
- RBC Stl Ql
- Synonyms
- RBC Stl Ql
- Category
- chemistry
- Sample
- stool
- Container
- Clean 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
- CPT
- 85041
- SNOMED
- 900000000000003001
- Specimen volume
- 5 g
- Stability
- Refrigerated: 24h, Frozen: 7d
- TAT
- 4–24 hours
- Order
- routine
What This Test Measures
Red blood cells are the most numerous cells in your blood. They contain hemoglobin, the protein that picks up oxygen in your lungs and delivers it to your tissues. This test counts how many red blood cells are present in a measured volume of blood.
Why It Is Ordered
Doctors order an RBC count as part of a complete blood count (CBC) to screen for or monitor anemia, to investigate fatigue or weakness, or to follow conditions that affect blood cell production or loss.
What the Results Mean
A low count may suggest anemia from blood loss, nutritional deficiencies, or problems with red cell production. A high count may occur with dehydration, certain lung or heart conditions, or blood disorders. Your doctor interprets the number together with hemoglobin, hematocrit, and other CBC results.
How the Sample Is Collected
A small blood sample is usually drawn from a vein in your arm. No special preparation is typically needed, though you should follow any instructions your care team provides.
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.
The RBC count is a core component of the complete blood count and is used alongside hemoglobin and hematocrit to classify and monitor anemia. It also helps identify conditions that raise red cell numbers and supports evaluation of overall blood health.
Short name
RBC Count
Frequently asked questions
Do I need to fast for this test?
Can my RBC count be affected by dehydration?
Should I worry if my result is outside the normal range?
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