Hematocrit is the volume occupied by red blood cells circulating in the blood. Its level is systematically measured during a blood test, in the complete blood count (NFS).
The hematocrit is the volume occupied by red blood cells circulating in the blood. It is expressed as a percentage. What is a normal rate? On the contrary, too high a rate? Too low ? What does it mean ? Properly interpret and understand their blood test results.
What is hematocrit?
Hematocrit (HTC) matches the ratio of red blood cell volume to total blood volume. Blood is made up of plasma (water and mineral salt) in which white blood cells circulate (see the diagram opposite), an essential component of the immune system, red blood cells, allowing the transport of oxygen throughout the body. and platelets, responsible for blood coagulation. So, the higher the number of blood cells per liter of blood, the higher the hematocrit.
What is the normal hematocrit level?
The hematocrit is dosed in such a way simple and accessible in the complete blood count (NFS), through a blood test. The hematocrit is between 40 and 55 % in men. In women, it varies between 35 and 50 %.
| Sex | Standards |
|---|---|
| Women | Between 35 and 50% |
| Male | Between 40 and 55% |
What does a high hematocrit mean?
The increase in hematocrit indicates polycythemia (increased number of red blood cells). Polycythemia may be primitive. This is the case in polycythemia vera. It’s about a disease that affects the bone marrow. These will be produced in too large quantities, which will increase their total volume. It may be secondary, due to heart diseaseTo tumors or at increased hormone synthesis which stimulate the production of red blood cells (erythropoietin). In cases of polycythemia, the blood is thicker and the main risk is the occurrence of thrombosis which can cause vascular accidents. Polycythemia can cause headaches, high blood pressure, dizziness, erythrosis of the skin (skin is red), and tinnitus (ringing in the ears). To note : the increase in volume and not in the number of red blood cells can also cause the hematocrit to increase. This is macrocytosis, common in cases of chronic alcoholism.
What does a low hematocrit mean?
The decrease in hematocrit translates, in most cases, anemia (decreased red blood cells or hemoglobin). It can have different causes:
- iron deficiency,
- inflammation,
- intestinal malabsorption (Biermer’s anemia),
- excessive blood loss.
Anemia can be microcytic, that is to say that the red blood cells are small, which decreases their volume and therefore the hematocrit. Anemia results in paleness, tiredness, increased heart rateheadaches and/or difficulty breathing (shortness of breath).
Hematocrit alone cannot provide a diagnosis. Its dosage must be supplemented by other examinationsin order to highlight a pathology. The hematocrit is dosed at the same time as hemoglobin levelred blood cell count, mean corpuscular volume (VGM), in the NFS. The interpretation of the hematocrit can only be done in addition to the interpretation of the rest of the blood cell count. “In case of anemia, remember to look at the mean corpuscular volume and the hematocrit already allows a good diagnostic orientation“, advises Dr Anne-Christine Della Valle, general practitioner.
When and who to consult?
An anomaly in the hematocrit noted on a routine check-up must push to consult a doctor because it must be interpreted according to all the other parameters of the blood formula. Depending on this and any symptoms, the workup will be expanded to find the cause.
What treatment when the hematocrit level is abnormal?
The treatment will depend on the pathology which caused the variation of the hematocrit. Treatment of anemia and its cause must be prompt. In the context of polycythemia vera due to polycythemia vera, bloodletting or treatment with certain medications are recommended.