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Whole Blood Hematocrit (Packed Cell Volume)

Published: August 9, 2026Updated: August 16, 2026

This test measures the proportion of red blood cells in your blood, helping assess red blood cell concentration and potential blood disorders.

Quick summary

["Hematocrit reflects red blood cell health and can signal anemia or polycythemia."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
25354-2
Short code
Wheat Bran IgG Qn
Synonyms
Wheat Bran IgG Qn
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
CPT
82784
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?

Hematocrit is the percentage of red blood cells in your blood sample, calculated by dividing the volume of red blood cells by the total blood volume. It’s a key part of your complete blood count (CBC).

Why Is It Tested?

Doctors may order hematocrit tests to diagnose or monitor conditions like anemia (low red blood cell count), polycythemia (high red blood cell count), dehydration, or blood disorders such as leukemia or sickle cell disease.

How Is It Done?

A small blood sample is drawn from a vein, typically in your arm. The sample is then analyzed to determine the percentage of red blood cells present.

What Are Common Results?

Results are typically reported as a percentage (e.g., 40-52% for men, 38-46% for women). However, reference ranges can vary by lab and individual health status.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings1

Short name

Hematocrit (HCT)

Frequently asked questions

What causes low hematocrit?
Low hematocrit can be caused by conditions like iron deficiency anemia, chronic diseases, heavy blood loss, or certain medications. Lifestyle factors such as poor diet or excessive alcohol use may also play a role.
What causes high hematocrit?
High hematocrit levels can result from conditions like polycythemia vera, dehydration, living at high altitudes, or lung diseases. Rarely, it may be due to blood doping or certain cancers.
How often should I get this test?
The frequency of hematocrit testing depends on your overall health, medical history, and any conditions you have. Your healthcare provider will determine the best schedule for you, often as part of routine blood work or monitoring of specific health issues.
  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 16, 2026. · Read our editorial policy