The hematocrit, also known as Ht or Hct, is a laboratory parameter that indicates the percentage of red cells, also known as red blood cells, erythrocytes or erythrocytes, in the total blood volume, being important to identify and diagnose some situations, such as anemia, for example.
The hematocrit value can also reflect the amount of hemoglobin present in red blood cells: when the hematocrit is low, it is usually indicative of a situation in which there is a decrease in the amount of red blood cells or hemoglobin, such as anemia, for example. When it is high, it can be indicative of low fluid in the blood, which can mean severe dehydration.
See also how to interpret hemoglobin values.
Hematocrit reference values
The hematocrit reference values vary by laboratory, but generally the normal hematocrit value is:
- Women: between 35 and 45%. In the case of pregnant women, the reference value is usually between 34 and 47%; Man: between 40 and 50%; Children from 1 year: between 37 and 44%.
The hematocrit value may vary between laboratories and must be interpreted together with the other parameters of the complete blood count. Even when there is a small change in the hematocrit value, it does not necessarily mean a health problem and, therefore, the result must be interpreted by the doctor who ordered the exam, in order to make the diagnosis based on the analysis of the result of all the requested exams. and symptoms described by the person, so you can start treatment if necessary. Learn how to understand the blood count.
What can be low hematocrit
The low hematocrit may be indicative of:
- Anemia; Bleeding; Malnutrition; Lack or decrease of vitamin B12, folic acid or iron; Leukemia; Excessive hydration.
During pregnancy, the low hematocrit is usually a sign of anemia, especially if the hemoglobin and ferritin values are also low. Anemia in pregnancy is normal, however, it can be dangerous for both mother and baby if not treated properly. Learn more about anemia in pregnancy.
What can be high hematocrit
The increase in hematocrit can happen mainly due to the decrease in the amount of water in the blood, with an apparent increase in the amount of red blood cells and hemoglobin, which is a consequence of dehydration. In addition, hematocrit may be increased in pulmonary diseases, congenital heart disease, when there is low oxygen levels in the blood or in cases of polycythemia, in which there is an increase in production and, consequently, excess red blood cells.
