EVF Blood Test (Erythrocyte Volume Fraction) – Hematocrit Explained
B-EVF (Erythrocyte Volume Fraction), commonly known as hematocrit, measures what percentage of your blood is made up of red blood cells. It is a core component of a complete blood count and is used to detect anemia, polycythemia, and dehydration. EVF provides a quick and reliable assessment of blood composition and oxygen-carrying capacity.
Why Test EVF Blood Test?
EVF testing is recommended to investigate symptoms of anemia or polycythemia, evaluate dehydration, monitor chronic conditions affecting blood production, and as part of routine health screening. It is also essential before surgical procedures.
What Do High EVF Blood Test Levels Mean?
High EVF values may indicate dehydration, chronic lung disease, smoking, high-altitude living, or polycythemia vera. Elevated levels increase blood viscosity and the risk of blood clots, stroke, and cardiovascular events.
What Do Low EVF Blood Test Levels Mean?
Low EVF values indicate anemia. Common causes include iron deficiency, B12 or folate deficiency, chronic disease, blood loss, pregnancy, and bone marrow disorders. Symptoms include fatigue, pallor, and shortness of breath.
Symptoms to Watch For
- Fatigue and reduced stamina
- Pale or flushed skin
- Shortness of breath
- Dizziness or headaches
- Blurred vision (with high values)
- Cold hands and feet (with low values)
Who Should Get Tested?
- Anyone with suspected anemia or polycythemia
- People experiencing dehydration symptoms
- Patients preparing for surgery
- Those with chronic heart or lung conditions
- Individuals undergoing routine blood screening
How to Prepare for Your Test
No special preparation is needed. Bring valid ID.
Frequently Asked Questions
Is EVF the same as hematocrit?
What is a normal EVF value?
How does EVF relate to hemoglobin?
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Wellth Team
Wellth
Our content is written and reviewed by Wellth, and fact-checked against peer-reviewed research and current Swedish clinical guidelines.
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The information on this page is provided for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment. Wellth provides health information and testing services but is not a substitute for clinical care. Always consult a qualified healthcare provider if you have questions about a medical condition. If you are experiencing severe or urgent symptoms, contact your doctor or call 1177 Vårdguiden. Blood test results should be interpreted by a qualified healthcare professional in the context of your complete medical history.