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Red Blood Cell Count (Automated Hematology)

Published: August 9, 2026Updated: August 17, 2026

This test measures the number of red blood cells in your blood, which helps assess your overall blood health and detect conditions like anemia or polycythemia.

Quick summary

["Red blood cell count helps diagnose and monitor blood disorders."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 17, 2026Editorial policy

Key facts at a glance

LOINC
784-9
Short code
MCD RBC Auto
Synonyms
MCD RBC Auto
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
automated-count
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 This Test Matters

Red blood cells carry oxygen from your lungs to the rest of your body and remove carbon dioxide. A low or high count can signal health issues, such as fatigue, infections, or blood disorders.

What to Expect Before the Test

No special preparation is needed. You may have a small needle inserted into your arm or hand to draw a blood sample. The process usually takes a few minutes.

How the Results Are Used

Your healthcare provider will compare your RBC count with standard values to check for abnormalities. Low counts may indicate anemia, while high counts could suggest conditions like dehydration or blood clotting disorders.

Common Conditions Affecting RBC Count

Low RBC counts (anemia) can cause fatigue, weakness, or pale skin. High RBC counts may lead to symptoms like headaches, dizziness, or increased risk of blood clots.

Reference range

Adult males: 4.2-5.9; Females: 3.8-5.1 x 10^12/LN/A

Specimen: serum

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

Frequently asked questions

What causes a low red blood cell count?
Low RBC counts can result from blood loss (e.g., heavy periods, injuries), poor nutrition (e.g., iron or vitamin deficiencies), chronic illnesses (e.g., kidney disease), or certain medications.
What causes a high red blood cell count?
High RBC counts may occur due to dehydration, lung diseases, or conditions that stimulate bone marrow overproduction (e.g., polycythemia vera). Lifestyle factors like smoking can also contribute.
How often should I get this test?
Your doctor may order this test periodically if you have symptoms of blood disorders, undergo regular check-ups, or are at higher risk for anemia or other hematologic conditions.
  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 17, 2026. · Read our editorial policy