Hematocrit
This test measures the proportion of red blood cells in your blood, helping assess your blood’s ability to carry oxygen and detect conditions like anemia or polycythemia.
["Hematocrit helps diagnose blood-related conditions by showing how much of your blood volume is made up of red blood cells."]
Key facts at a glance
- LOINC
- 41986-1
- Short code
- HEMATOCRITTESTSTATUSORRESULTS
- Synonyms
- —
- Category
- hematology
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Ref low
- 36
- Ref high
- 50
- Critical range
- 18 N/A – 60 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- cphs
- CPT
- 85014
- 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 It’s Done
Doctors may order a hematocrit test to check for signs of anemia (low red blood cell count), polycythemia (high red blood cell count), dehydration, or other blood disorders. It’s also used before surgeries, during pregnancy, or if you have symptoms like fatigue, dizziness, or unusual bleeding.
How It’s Done
A small blood sample is taken from a vein, usually in your arm. The sample is then analyzed to determine the percentage of red blood cells relative to the total blood volume.
What to Expect
The process is quick and painless, similar to a routine blood draw. You may feel a slight pinch, but most people tolerate it well. Results are typically ready within a few hours or the next day.
Normal vs. Abnormal Results
While reference ranges vary by age, gender, and health status, lower than expected hematocrit levels may suggest anemia or blood loss, while higher levels could indicate dehydration, polycythemia, or other conditions.
Reference range
Adult males: 38-50%; Females: 36-44%N/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Hematocrit is a key indicator of red blood cell health. Low levels often point to anemia or iron deficiency, while high levels may signal overproduction of red blood cells (e.g., due to lung disease or polycythemia vera). It’s also used to monitor treatments for blood disorders or conditions like kidney disease.
Short name
Hematocrit Test
Frequently asked questions
What causes a low hematocrit?
What causes a high hematocrit?
How long does it take to get 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 17, 2026. · Read our editorial policy