What does hematocrit answer? Decreased and elevated hematocrit

Each of us has done a blood test at least once in our life. The purpose of its conduct, along with other characteristics of our blood, is to determine Ht - an indicator of hematocrit. It is great if it is normal, because both high and low hematocrit indicate any pathologies in the body. However, a deviation of Ht in one direction or another does not mean at all that the subject has an incurable disease. It only means that you need to conduct a deeper examination and find the cause of such blood test indicators.

What is hematocrit

The hematocrit (Ht) is also called the hematocrit number or value. This indicator determines how much of a unit of blood volume is occupied by the volume of erythrocytes. Sometimes the Ht number is an indicator of how much of a unit volume of blood is occupied by erythrocytes together with leukocytes and platelets. Given that 99% of these three particles are red blood cells, the difference between the two readings is very small. The hematocrit is measured as a percentage, less often in milliliters per liter. In the latter case, the indicator is calculated to the second decimal place. For example, 35% = 0.35 = 350 ml of red blood cells per 1 liter of blood.

In addition to the blood count, a special measuring device is also called hematocrit - a thin glass tube with a scale. With its help, the level of red blood cells, leukocytes and platelets in the blood is measured.

Hematocrit values

It is generally accepted that the average value of the normal hematocrit for men is in the range of 0.4 - 0.48, and for women in the range of 0.36 - 0.46. Although some doctors are inclined to believe that for men aged 15 years and older, the Ht readings are 0.35-0.5, and for women (also from 15 years old) 0.34-0.47 is also the norm. There is also a gradation of Ht in relation to the patient's age. The younger the person, the lower the hematocrit reading. Newborn babies usually have a hematocrit 20 percent higher than adults. This is considered the norm. Gradually, babies experience a decrease in hematocrit, and by about a year or two, its value becomes slightly lower than in adults. In addition to age, the value of Ht is influenced by the size of erythrocytes. There are various reasons due to which the level of red blood cells increases or decreases. For example, a lack of iron causes a decrease in the size of red blood cells. In this case, their volume and, therefore, Ht readings will be low, but their total number per unit volume of blood may be normal.

What is the risk of increased hematocrit

By analogy with hemoglobin, some patients tend to believe that only a low hematocrit is dangerous. However, if its number is equal to or higher than the 0.55 mark, additional surveys should be carried out. A high level of red blood cells in the blood leads to thickening and contributes to the formation of blood clots. Increased hematocrit can be caused by various diseases, such as: diseases of the hematopoietic system; tumors in the uterus; adrenal gland disease; diseases of the lungs and kidneys; extensive burns; peritonitis. In healthy people, this blood condition can be observed:

High in the mountains, where the atmosphere is thin;

At open-hearth furnaces or with prolonged exposure to high temperatures;

With dehydration.

Causes of low hematocrit

Reduced hematocrit can be caused by the following reasons:

Oncological diseases of the bone marrow;

Cirrhosis of the liver;

Acquired or hereditary anemias;

Bleeding, large blood loss;

Pathological hemolysis (rupture of red blood cells);

Hemoglobinopathy;

Artificial heart valve transplant;

Disturbances in the hemoglobin reproduction system;

Overhydration (when a person receives a lot of liquid drugs intravenously);

Chemical poisoning (mushrooms, bites of poisonous insects and snakes, and others);

Lack of iron, vitamin B12 or folic acid in the body;

Improper nutrition;

Last months of pregnancy.

Why is low hematocrit dangerous?

Red blood cells - erythrocytes - are very important for human life, as they are the suppliers of nutrients and oxygen to all cells of the body. Also, erythrocytes take carbon dioxide from the cells. If the hematocrit is low, that is, the volume of erythrocytes per liter of blood is less than normal, the cells of the human body experience oxygen starvation, the acid-base balance and the order of work of all organs are disturbed. If Ht is much lower than normal, a person may experience general malaise, high fatigue, shortness of breath, and frequent headaches. The most common cause of low hematocrit is anemia. Many people do not take this diagnosis seriously enough, because in the early stages nothing hurts them. At the same time, anemia (or else they say - anemia) is a syndrome of a number of diseases. In pregnant women, low hematocrit occurs due to the fact that a large amount of iron is consumed for the formation of erythrocytes of the future baby. Its lack in the mother's body leads to a decrease in the formation of her own red blood cells and, as a result, the development of anemia.

What to do if the hematocrit is higher or lower than normal

If the blood test results show that the hematocrit is low or high, do not panic. Doctors will definitely conduct additional examinations to find out the cause of the deviation from the norm. If necessary, treatment is prescribed, but often, especially with a low hematocrit, the patient needs to organize proper nutrition, including all the necessary vitamins, and also to reconsider his attitude to smoking and alcohol. Pregnant women in whom a low Ht count is caused by a lack of iron are prescribed preparations containing this element. As a rule, the use of drugs according to the doctor's prescriptions completely restores the hematocrit in the blood.

The materials are published for information purposes only, and are not a prescription for treatment! We recommend that you consult a hematologist at your hospital!

When taking a blood test, patients usually do not ask doctors what hematocrit is. Meanwhile, this blood count in case of deviation from the norm indicates pathological conditions, which requires a thorough examination.

Hematocrit is a value that measures the ratio of the total volume of blood components - erythrocytes, platelets, and leukocytes - to the total blood volume. Since platelets and leukocytes make up only about 1% of the total cell volume, often when calculating the indicator, only erythrocytes are taken, which carry out the function of transporting oxygen through the cells of the body.

Measuring indicators

How to calculate the hematocrit in the blood? As an example, we will give a way to measure this indicator with the naked eye. It is necessary to collect blood and let it stand for a while, waiting for the erythrocytes to settle. Then see how many percent in the blood volume of erythrocytes and how many percent is occupied by plasma.

Note. Doctors have a special formula for calculating the hematocrit level. The content of erythrocytes in the blood (in%) or its expression as a fraction (liter per liter), multiplied by 0.01 - the result obtained is the hematocrit.

Rate of indicators

What is hematocrit in a blood test and what should be the norm? Determination of the level of this indicator is carried out using a special tube in which the blood is located. It is centrifuged and analyzed to see what percentage of the volume is occupied by different components of the blood.

The hematocrit rate depends on the sex and age of the patient. If we talk about the norm of hematocrit in women, then it is 36-42% of the total blood volume, in men it is slightly higher - 44-48%, and in newborns the hematocrit is usually significantly increased - 54-68%.

The table of the norm of indicators of hematocrit

Important. If the volume of the hematocrit is changed, then this indicates that either the person's blood is too thick, or it is very thinned.

Reduced level

What is the reason for the low hematocrit? If the volume of erythrocytes in the blood is significantly reduced and is about 20-25%, then such conditions are usually called. The causes of such an anomaly can be an excess amount of water in the body (this condition is called overhydration), a sharp drop in the red blood cell count (erythropenia), or a large accumulation of proteins that prevent excess water from leaving the body (hyperproteinemia).

Briefly about exceeding the norm

What does elevated hematocrit indicate? A high indicator means, first of all, that the level of red blood cells in the blood has increased or they have increased in size.

© Use of site materials only by agreement with the administration.

It is doubtful that a patient who is studying a general blood test taken the other day and performed on an automatic analyzer will be primarily interested in such an indicator as hematocrit. Unless doctors, in a conversation with each other, drop about its meanings or tell the patient if its level does not fit into the norms and causes concern on the part of doctors.

Hematocrit is the ratio of red blood cells to total blood volume. The approximate level of this indicator can be seen with the naked eye, if you let the blood settle, and then estimate by eye how many percent the settled ones take and how much remains for the plasma fraction. Meanwhile, this technique is presented only with the purpose of explaining to the reader with a simple example what hematocrit is, but not as a means of calculating the indicator independently. With spontaneous erythrocyte sedimentation, the hematocrit number will be almost 20% higher, so this technique is not used in laboratory conditions. Percentage of red blood cells in whole blood, fractional expression (liters in liters) or multiplied by 0.01 a percentage result called hematocrit, measured manually using the necessary tools or calculated in an automatic analyzer.

The norm of hematocrit for gender and age

Normally, the body of an adult contains approximately 4.5 - 5 liters of blood, which is represented by a red heavy part (erythrocyte mass), when settling down to the bottom, and a light yellowish liquid (plasma), if the blood was taken with an anticoagulant. Blood taken in dry dishes without the use of anticoagulants forms a fibrin clot with erythrocytes adhered to it and a liquid part - serum, which is more transparent and differs from plasma by the absence of fibrinogen protein in it. Until the blood has left the bloodstream, it exists in the form of plasma with circulating corpuscles (leukocytes, erythrocytes, platelets), coagulation factors and other proteins. Serum is devoid of many components.

The erythrocyte mass in males is approximately 44 - 48% or 0.44 - 0.48 l / l. In women, of course, this indicator is lower (36 - 42%), and in newborns it can generally be high - 54 - 68% (N - 0.44 - 0.62).

This is the hematocrit rate in percent, which, for convenience, is multiplied by 0.01 and the values ​​are obtained:

• Norms of hematocrit for men: 0.44 - 0.48 (in some sources up to 0.52, which may well be, because male blood is not renewed as often as female);
• Norms of hematocrit for women: 0.36 - 0.43, however, during pregnancy (from 20 weeks) the hematocrit decreases;
• In children: newborns - 0.44 - 0.62, babies up to 3 months - 0.32 - 0.44, up to a year - 36 - 44 (like women), up to 10 years - 37 - 44, and then everything depends on gender and health conditions.

A change in the hematocrit volume of erythrocytes in one direction or another may indicate either the degree of blood concentration, or how much the blood is diluted.

When the hematocrit is lowered ...

It is not difficult to guess that the hematocrit values ​​directly depend on erythrocytes, or rather, on their size and number. If, for some reason, there are a lot of them (hematocrit is increased) or too little (hematocrit is lowered), or their sizes, due to certain circumstances, begin to change in the direction of decreasing or increasing. Of course, the volume of the cellular part of the blood will proportionally deviate in the appropriate direction. A low hematocrit is said if its level drops to 20-25%, which indicates about. As a rule, such changes are caused by factors involved in the formation of the pathological process.

The reason for a decrease in hematocrit can be a drop in the level of red blood cells (erythropenia), excessive accumulation of water in the body, which dilutes blood and changes the percentage of red blood cells and plasma (overhydration), or an excessive increase in the concentration of proteins (hyperproteinemia) that bind and retain water in the body. Such changes are observed under the following circumstances:

1. , but if the volume of circulating blood (BCC) can be restored relatively quickly with infusion solutions, then it takes a certain time for erythrocytes to return to normal.
2. In the bone marrow, the formation of red blood cells is impaired (reduced)(anemia, treatment with cytostatics and antineoplastic drugs, renal paresis).
3. Red blood cells are intensively destroyed: hereditary and acquired hemolytic anemias, hemolytic poisoning (pale grebe, heavy metal salts), serious infections (typhoid fever, malaria).
4. Intravenous injection of large amounts of fluid in patients with impaired renal function, the total blood volume increases with normal red blood cells, naturally, this leads to the fact that the hematocrit number becomes lower.
5. The hematocrit is lowered during pregnancy, especially in the second half, which is due to an increase in plasma volume while maintaining the same level of red blood cells.
6. Anemia of any kind and origin.
7. Hyperhydration: BCC increases, the content of erythrocytes remains unchanged - the hematocrit is lowered (water intoxication, circulatory failure, decreased functional abilities of the excretory system, etc.).
8. Hyperproteinemia. It is formed by a wide range of conditions varying in severity: vomiting, diarrhea, acute infections, paraproteinemic hemoblastosis. An increase in protein in the blood ultimately leads to the accumulation of fluid in the body and an increase in the BCC (erythrocytes remain indifferent to these changes).

For children, there are no separate reasons for a lowered hematocrit, therefore, a drop in the level of this indicator in a child obeys the same law as in an adult, except that the baby's body is more sensitive to such changes and the disease is often somewhat more severe.

... Or upgraded

The main reason for an increase in hematocrit is an increase in the number of red blood cells (overproduction in the bone marrow) or an increase in their size, which creates additional volume.

Thus, the hematocrit is increased in all diseases and conditions caused by a change in the number or size of red blood cells:

The causes of an increased hematocrit of a relative nature can be transient conditions:

1. Intestinal obstruction (fluid transfer there);
2. Frequent vomiting;
3. Profuse diarrhea (thickening of the blood);
4. Hyperhidrosis (intense sweating);
5. Burn disease;
6. Inflammation of the peritoneum (peritonitis);
7. Highland conditions.

Obviously, an analysis only for hematocrit without determining the number of erythrocytes and their morphological features is unlikely to be able to satisfy the requests of clinicians in the diagnosis of various hematological pathologies, since the test, although it carries general information, does not reveal the cause of the increase or decrease in any way. Usually hematocrit is included in the list of indicators of the general blood test, where it can be compared with other parameters (erythrocytes, color indicator). However, the hematocrit may be one of the first signals to conduct a comprehensive examination of the patient in order to find the reason for the decrease or increase in the indicator, or rather, the disease well disguised at first.

Video: a lesson on red blood cells and blood functions

Hematocrit is an indicator, the values ​​of which in a general blood test tell little to most people. Hematocrit is the number of red blood cells in total blood volume. The average hematocrit values ​​can be determined even with the naked eye, if blood is taken and allowed to settle. Red blood cells that have settled to the bottom will indicate the hematocrit as a percentage compared to the rising blood plasma. This example is presented with the aim of making the reader understand what constitutes hematocrit, and not for the purpose of a guide to further self-determination of the level of red blood cells in the blood. The fact is that spontaneous erythrocyte sedimentation will exceed the hematocrit by 20% or more, therefore, in laboratory conditions, the hematocrit is not determined by eye, which is quite logical.

The hematocrit is determined as a percentage, calculated in whole blood. It can also be presented in fractional values ​​or multiplied by 0.01 as a percentage. The indicator is calculated using special devices, or manually.

Each person has about 4.5-5 liters of blood in his body. It consists of heavy red blood cells and light-colored light plasma. When standing, red blood cells go down, and plasma rises up if blood was collected using an anticoagulant.

If the analysis is taken in a dry test tube, then the blood coagulates, forming a fibrin clot. It will contain red blood cells and serum. It differs from plasma in a lighter color, since it does not contain fibrinogen (a protein component). In the human body, blood is represented by plasma with platelets, erythrocytes and leukocytes dissolved in it, as well as other proteins. Most of the components are absent in blood serum.

Normal hematocrit readings for different categories of patients:

Men: 0.44-0.48, and sometimes up to 0.52. Such high values ​​are indicators of the norm, since male blood is renewed less often than female.

Women: 0.36-0.43. During pregnancy, starting from the 20th week of the term, the hematocrit level begins to decrease.

Children: 0.44-0.62 - for newborns, 0.32-0.44 - for infants up to 3 months, 0.36-0.44 - for children under one year, 0.37-0.44 - for children up to 10 years. In the future, the indicators of the norm are determined by the sex of the person and the state of his health.

A decrease and an increase in the blood hematocrit indicates the degree of concentration of red blood cells in it.

The fewer erythrocytes in the blood and the smaller their size, the lower the hematocrit level. If the hematocrit value drops to 20-25%, then the person is diagnosed with anemia. The cause of this condition may be a decrease in the level of red blood cells in the blood. This condition is called erythrocytopenia. Also, a low hematocrit is observed with the accumulation of water in the body - this condition is called overhydration. Hematocrit will decrease as the level of proteins in the body increases, which contribute to fluid retention. This condition is called hyperproteinemia.

Causes of low hematocrit:

Burn disease.

Inflammation of the tissues of the peritoneum.

Finding a person at significant altitudes (mountain sickness).

The hematocrit level, as a single indicator, is not able to confirm any specific diagnosis, since it gives only generalized information about the state of human health. Therefore, it is important to know other blood parameters that allow one to suspect certain violations. Nevertheless, pathological changes in the level of blood hematocrit should alert the doctor and become the reason for a high-quality and comprehensive examination.

Video lesson on red blood cells and blood functions:

Education: In 2013 he graduated from the Kursk State Medical University and received a diploma "General Medicine". After 2 years, completed residency in the specialty "Oncology". In 2016 completed postgraduate studies at the National Medical and Surgical Center named after N.I. Pirogov.

A general blood test allows you to get quite extensive information about a person's condition. One of the indicators that you will find in the analysis is hematocrit, but not everyone knows the norm, so decoding becomes difficult. However, it is not so difficult to figure out what this indicator means, as well as what its deviations indicate.

Hematocrit is understood as an indicator of the conditional value that can be obtained when prescribed for a general blood test. It denotes what is the ratio of blood cell volume to total blood volume in percentage terms. Sometimes the analysis can be performed with measurement only of erythrocytes, which will also be true, since they are the main constituent of blood.

In the analysis, the hematocrit rate is not always indicated, and most often it is indicated by a combination of HCT, that is, the decoding is assumed for this line in the analysis. Moreover, the more correct term is the hematocrit number. The hematocrit itself is a glass flask that is used in the analysis of blood for centrifugation. This number can also be called "blood density", this is the definition for HCT is common among the people.

Measured HCT as a percentage. However, sometimes decryption is performed in decimal fractions, while the accuracy reaches hundredths.

It is necessary to check whether the hematocrit is normal in several cases. The most common is surgery as well as pregnancy. The hematocrit during pregnancy is determined to eliminate the risk of women losing large amounts of blood during childbirth. A complete blood count is the first priority in the diagnosis of any disease. Specifically, doctors require HCT when there are varicose veins in the lower extremities, suspicions of an autoimmune disease or liver problems.

Blood coagulability, by and large, for humans is a protective type of reaction. This helps to protect the body from large blood loss. The endocrine and nervous systems are responsible for the process of regulating coagulation. In this case, a violation of the flow of blood can lead to blockage of blood vessels.

Only being in a liquid state, blood can fulfill such an important purpose as transporting nutrients, protecting the body, performing trophic and thermoregulatory functions.

A general analysis can show what blood clotting is. An increase in HCT means an increased risk of thrombosis, heart attack and stroke. That is why doctors insist on the constant delivery of general blood tests.

Indicators of the norm and increase

Speaking about the rate of HCT, we can distinguish the so-called conditionally normal level. In particular, for women it ranges from 35 to 42 percent, for men from 40 to 47 percent. The child's norm should not exceed 44 percent and be below 32. However, you need to understand that such an average indicator means that the change in HCT level depends on gender and age.

In particular, girls under the age of 18 have a higher HCT rate than boys. However, in adults, things are somewhat different. For women under the age of 45, the indicator in the analysis is from 35 to 45 percent. For women over 45, the indicator should be in the range of 35-47 percent.

For men, the norm from the age of majority to 45 years is at least 39 and not more than 49 percent. For the older generation, only the upper limit changes, it should not exceed 50 percent.

However, HCT does not always remain within the normal range, sometimes the interpretation of the analysis indicates an increase in the indicator. There may be several reasons for this:

• prolonged hypoxia;
• dehydration;
• oncological diseases of the blood and kidneys.

Speaking of prolonged hypoxia, we mean a lack of air. We are not talking about suffocation, but about the fact that an insufficient amount of oxygen enters the bloodstream. As a result, hemoglobin rises, the body also begins to increase the amount of erythrocyte. A general analysis will reveal such an increase in HCT in people with respiratory problems, smokers, mountaineers or hikers who are often in mountainous areas.

Dehydration is another common cause of high HCT. . Dehydration can often be found with peritonitis, diseases of an infectious nature, problems with housing and communal services and burns.

Unfortunately, deciphering an analysis with a high hematocrit can be the first step in determining oncological diseases of the blood and kidneys. Increased blood density is a mandatory attribute of leukemia or kidney tumors. If the decryption leads the doctor to exactly this conclusion, the patient will be assigned additional studies that will reveal the exact reason for the increase.

Decreased indicator

As a result of the analysis, you can meet not only an increased, but also a reduced hematocrit. Often, the cause of a decrease in the hematocrit number is anemia, which has a hypoplastic nature. Overhydration can also cause low HCT. In this case, we are not talking about a large intake of fluid, but about its presence in the blood. The reason for this condition may be kidney problems, poisoning, diseases of an infectious and viral nature.

Hyperproteinemia also cannot be excluded from the list of possible causes. In this case, the protein draws water on itself, which leads to a decrease in blood density. Elevated levels of proteins in the blood may be due to liver damage.

The hematocrit also decreases during pregnancy. This reason is physiological. If for healthy women the indicator should not be lower than 35 percent, then in pregnant women numbers 33-32 are often found. This is due to testing the body for strength by additional loads. As a result, various diseases may appear, from which the woman has not previously suffered, and this leads to a decrease in HCT to low levels. In this case, the level of HCT will proportionally depend on the number of fetuses in the womb. In a twin pregnancy, the hematocrit rarely rises above 30 percent.

The HCT level helps to determine the physiological hydremia in a woman. This does not mean that oxygen transfer in the blood is poor. This is due to erythrocidal hyperplasia of the bone marrow. This is a common condition in pregnant women in which the number of red blood cells in the blood increases. In this case, an increase in the plasma amount becomes the cause of hydremia.

Closer to childbirth, the hematocrit level rises to protect the body from blood loss during rupture. That is why it is very important to determine the reason for the lowered number. Physiological features should not scare you, but a decline due to illness requires treatment.

Experts emphasize that a decrease in hematocrit often causes a decrease in iron in the body. This becomes the cause of the development of first degree anemia. It is very important that during pregnancy a woman receives iron in sufficient quantities, otherwise after childbirth, you may encounter a large shortage of it.

Increasing the level of iron can be achieved with the help of drugs of the drug type, which contain the necessary element in the right concentration. The course of treatment is selected individually by a specialist. It is not bad to connect a complex of juices and multivitamins to medicines.

If a woman suffers from poor glandular absorption, then parenteral administration is used. The course of treatment usually does not exceed three weeks. At the same time, despite the presence of anemia in the mother, the child will not have problems with the hematocrit number. However, due to the lack of large reserves of this element in the body, its level can drop sharply, which is normalized with the help of a balanced diet.

In women with this condition, a lack of iron and folic acid can be observed. This is a fairly common occurrence. Such insufficient indicators indicate a small number of erythrocytes in the blood.

An increase in hematocrit during pregnancy occurs in some women. This suggests that the density of the blood has increased, and, accordingly, there is a risk for the work of the cardiovascular and nervous systems of the expectant mother. Equally important, elevated HCT can cause fetal hypoxia. This entails developmental problems, and can also be the cause of death.

Increased hematocrit in pregnant women is most often observed due to dehydration, which is caused by early toxicosis. Vomiting, especially when combined with diarrhea, quickly dehydrates the body. All this can be accompanied by excessive sweating, which is caused by hormonal disruption. Also, do not forget about observing the drinking regime, especially in hot weather conditions.

Late toxicosis is observed in women much less often, but it cannot be excluded from the list of possible causes. Late toxicosis is the result of malfunctioning of the kidneys, liver or heart. It is also worth checking the nervous system and the placenta. Improper diet, in particular, the abuse of salty foods, can increase HCT levels.