Whole Blood Hematocrit (Hematocrit, Packed Cell Volume)
This test measures the proportion of red blood cells in your blood, which helps assess your blood’s ability to carry oxygen and detect conditions like anemia or polycythemia.
["Hematocrit reflects red blood cell volume and can signal blood disorders or hydration status."]
Key facts at a glance
- LOINC
- 53226-7
- Short code
- WBC #/area Urth Wet Prep
- Synonyms
- WBC #/area Urth Wet Prep
- Category
- chemistry
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 4.5
- Ref high
- 11
- Critical range
- 2 N/A – 30 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- wet-preparation
- CPT
- 85004
- SNOMED
- 900000000000003002
- 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
What Is Hematocrit Used For?
Hematocrit is primarily used to diagnose and monitor conditions affecting red blood cell production, distribution, or destruction. It helps evaluate anemia (low red blood cells), polycythemia (high red blood cells), or dehydration. Doctors may also use it to guide treatments for conditions like chronic kidney disease or blood loss.
How Is the Test Performed?
A small blood sample is drawn from a vein, typically in your arm. The blood is then separated into components using centrifugation, and the percentage of red blood cells (hematocrit) is measured.
What Does a Low or High Hematocrit Mean?
A low hematocrit may indicate anemia, blood loss, or overhydration. A high hematocrit could signal dehydration, polycythemia, or lung disease. Your doctor will interpret results in the context of your symptoms and medical history.
Common Conditions Affecting Hematocrit
Conditions like iron deficiency anemia, kidney disease, or certain cancers can alter hematocrit levels. Chronic conditions such as heart failure or liver disease may also impact red blood cell production.
Reference range
Adult: 4.5-11.0 x 10^9/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
Hematocrit (HCT)
Frequently asked questions
Why might my doctor order a hematocrit test?
What are typical reference ranges for hematocrit?
Can lifestyle changes affect hematocrit results?
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 16, 2026. · Read our editorial policy