Contents
In line with its mission, the Editorial Board of MedTvoiLokony makes every effort to provide reliable medical content supported by the latest scientific knowledge. The additional flag “Checked Content” indicates that the article has been reviewed by or written directly by a physician. This two-step verification: a medical journalist and a doctor allows us to provide the highest quality content in line with current medical knowledge.
Hematocrit is the percentage of blood cells in its total volume. Since the vast majority of them are erythrocytes, then, as a rule, this indicator reflects the amount of these structures in relation to plasma. It can change up or down in some diseases and helps in their diagnosis.
Our commitment in this area has been appreciated, among others, by by the Association of Journalists for Health, which awarded the Editorial Board of MedTvoiLokony with the honorary title of the Great Educator.
What is hematocrit? How should the hematocrit results be interpreted? What does low hematocrit testify to? Does low hematocrit mean serious medical conditions? The question is answered by the drug. Paweł Żmuda-Trzebiatowski.
The value of the norm of hematocrit in humans
The body of a healthy adult contains approximately 4.5-5 liters of blood. It contains formed elements and cells – erythrocytes, platelets, leukocytes, as well as the liquid part, called plasma.
Some blood components, for example, erythrocytes, do not have all the necessary components of a human cell, losing them in the process of maturation. Therefore, erythrocytes and platelets are called blood cells, not cells.
In different categories of patients, the normal values of various parameters of the studied blood will differ. So, in most men, the hematocrit will be higher: 40-41%, and in some cases it can reach up to 51%, which is associated with its slower renewal.
In healthy women, the hematocrit is usually in the range of 36 to 42%. This is due to the peculiarities of physiology – due to regular menstrual bleeding, the blood is updated more often to replenish its volume. During pregnancy, from the 20th week, the indicator begins to decrease, which is also not considered a deviation.
In children, hematocrit differs at different age periods:
- 44-62% for newborns;
- 32-43% for babies up to three months;
- 36-43% for children under one year old;
- 35-47% (up to 52% for boys) – in the first ten years.
In subsequent years, the hematocrit norm depends on gender and practically corresponds to the values in an adult.
Methods for determining hematocrit
The indicator is determined as a percentage, calculating the number of formed elements in whole blood. It is calculated using special instruments or manually.
Wintrobe centrifugation
The blood is subjected to centrifugal force for 10-30 minutes. The shaped elements are heavier than plasma, so they settle to the bottom of the tube. The hematocrit is determined by the ratio of the sediment to the total volume of the biomaterial.
Calculation of the indicator using the formula
The ratio of the number of red blood cells to the total blood volume can be calculated mathematically. For this, the following indicators are required:
- concentration of total hemoglobin (ctHB);
- red blood cell count (RBC);
- mean cell volume (MCV);
- mean concentration of hemoglobin in an erythrocyte (MCHC).
Hematocrit (HCT) is determined by one of the formulas:
- HCT (%)=(ctHB (mmol/l)*0.0485+0.0083)*100
- HCT (%)=0.1*MCV*RBC
- HCT (%)=ctHB/MCHC*100
Method of direct counting of blood cells
In a given volume of biomaterial, visible blood cells are counted manually or using hematological analyzers. The method has high accuracy, and the measurement process does not take much time – no more than five minutes, but the equipment required for this is very expensive.
Manual counting method
The blood taken with the use of an anticoagulant is placed in a dry, clean test tube and allowed to settle. In this case, the shaped elements, which have a greater weight, settle to the bottom of the tank, and the light plasma rises to the top, and two fractions of red and yellow are formed, respectively. By divisions on a test tube, you can determine the hematocrit. This method is the least accurate, its error is up to 20%, so it is not currently used in laboratories.
When is a hematocrit test performed?
Most often, hematocrit is determined in the composition general (clinical) blood test. Therefore, at present, this CBC parameter is not assigned separately. The hematocrit level changes with:
- disorder of the blood coagulation system;
- dehydration;
- anemia or polycythemia;
- bleeding.
Assessment of hematocrit is important in determining the indications for the need for blood transfusion or the effectiveness of blood transfusion, in hemodialysis, and some operations. To determine the hematocrit, venous or capillary blood is taken.
Increase in hematocrit
An increase in hematocrit occurs with an increase in the number of blood cells – polycythemia – and a lack of fluid in the body. An increase in the indicator may indicate serious diseases accompanied by blood clotting and thrombotic complications.
Causes
Hematocrit increases against the background of stress, taking corticosteroid drugs and diuretics, traumatic shock, accompanied by intense pain, as well as when climbing to high altitudes, smoking, playing sports using anabolic steroids to gain muscle mass.
An increase in the indicator may also indicate the following diseases:
- dehydration due to vomiting, profuse diarrhea, overheating of the body or heat stroke, profuse sweating, insufficient drinking;
- severe bleeding in the midst of or immediately after it stops;
- pathologies accompanied by a decrease in blood plasma volume, for example, peritonitis, thrombosis, diabetes, burn disease;
- violation of the kidneys – hydronephrosis, oncology, polycystic;
- vitamin B12 or iron deficiency anemia;
- leukemia;
- erythrocytosis;
- malformations and ischemic heart disease, heart failure;
- intestinal obstruction;
- bronchial asthma, pulmonary emphysema, obstructive bronchitis.
Symptoms
An increase in blood viscosity leads to thrombosis. The latter can manifest itself in the form of tingling or various pains and numbness in the limbs. If the cause of increased blood viscosity is not determined in time, serious complications such as myocardial infarction, stroke, gangrene, and even death may develop.
Treatment
Treatment is not for the altered hematocrit level itself, but for the conditions or diseases that caused these changes. In a number of situations where serious causes for a slightly altered hematocrit level have been ruled out, no treatment is required. But usually such situations are short-term, in the case of physiological causes of changes in the hematocrit level.
Decreased hematocrit
A reduced hematocrit occurs when the number of red blood cells or their size decreases – erythrocytopenia. The cause may be the accumulation of water in the body, when the blood becomes more liquid – overhydration, as well as hyperproteinemia or the accumulation of proteins in the plasma, contributing to fluid retention.
Causes
A decrease in hematocrit is facilitated by prolonged immobility, fasting or a strict diet, taking anticoagulants and antiplatelet agents, intravenous infusions in large volumes; heavy drinking, chronic alcoholism, excessive salt intake, menstruation in women.
Also, a downward change in the indicator may indicate the following pathologies:
- iron, B12 or folic deficiency anemia;
- severe bleeding;
- violation of hemoglobin production in sickle cell anemia;
- fibrous degeneration of the liver – cirrhosis;
- disruption of the urinary system;
- hemolysis of erythrocytes – the destruction of red blood cells due to hereditary mutation, autoimmune processes or toxic effects on blood cells;
- malaria, typhoid fever;
- oncological diseases of the bone marrow or its metastatic lesion from other organs;
- an increase in the amount of protein in the plasma against the background of vomiting, diarrhea, blood cancers and other conditions.
During pregnancy, a decrease in hematocrit can be observed in case of toxicosis, a very young age of the mother, multiple pregnancy, a short period of time between pregnancies, and also after the 20th week of gestation due to a physiological increase in fluid in the body.
Symptoms
A decrease in hematocrit in the blood is accompanied by hypoxia of various organs, since it is red blood cells that normally carry oxygen throughout the body. This condition is manifested by the following symptoms:
- fast fatiguability;
- general weakness;
- drowsiness;
- rapid heartbeat and breathing;
- feeling short of breath;
- headache, dizziness;
- decreased memory and concentration;
- hair loss;
- marbling or pallor of the skin.
Treatment
A decrease in hematocrit in an adult to 35-30% requires outpatient observation by a doctor, the exclusion of possible serious diseases, diet correction with an increase in the consumption of animal products, in particular, red meat and liver, leafy greens. A rate below 13% is characteristic of life-threatening pathologies and is usually detected in patients in serious condition in the hospital. The tactics of patient management is determined by the underlying disease, which led to a change in the hematocrit level.
What does low hematocrit show?
Hello. I would like to ask what it involves low hematocrit. Recently, such a result appeared in the blood tests of my 43-year-old husband. I would like to emphasize that my husband does not have any special health problems, he is well and he does not suffer from any chronic diseases. The hematocrit was not significantly lowered, but was nonetheless abnormal. The husband rather ignores it, claims that he is an example of good health and does not want to go to the doctor with the results. However, I can’t stop thinking about these results and I’m just afraid.
What is low hematocrit associated with? What does this result mean at all? I don’t even know what hematocrit is, I don’t have much medical knowledge … Could low hematocrit mean some disease in my husband and should he actually see a doctor? Or is it I am exaggerating and there is no reason to be concerned about this one result? The rest of my husband’s blood tests were normal, the problem is just the hematocrit. I know my husband works hard and doesn’t have a lot of time, but if it turns out to be something serious, maybe he’ll see a doctor … Please help.
The doctor indicates possible reasons for the decrease in hematocrit
Dear madam, it is a pity that you did not write how exact it is hematocrit result and other tests, in particular hemoglobin and erythrocytes. Low hematocrit may indicate an overhydration of the body. The excess fluid in the body causes the number of blood morphotic elements per unit volume to decrease, and as we know, hematocrit is the ratio of the erythrocyte volume to the plasma volume.
Most often, however, decreased hematocrit is associated with iron deficiency anemia, the so-called anemia microcytarnand. In addition to a reduced hematocrit, iron deficiency anemia is also indicated by a decrease in the amount of hemoglobin and erythrocytes, as well as a decrease in the size of erythrocytes – hence the term microcytic. Iron deficiency anemia is also known as hypochromatic (hypochromatic) due to the reduction in hemoglobin which makes red blood cells red.
Your husband’s results should be compared with the state of health, are there any symptoms that bother you? Iron deficiency anemia symptoms include weakness, chronic fatigue, pale skin, mouth inflammation, irritability and hair loss.
It would be best if your husband would be persuaded to visit a primary care physician who will collect a detailed interview with the patient and order appropriate tests, including laboratory tests of blood, in particular the concentration of iron and ferritin. Of course, I am not suggesting that your husband suffers from any disease, but a visit to the doctor is absolutely recommended.
For a long time you have not been able to find the cause of your ailments or are you still looking for it? Do you want to tell us your story or draw attention to a common health problem? Write to the address [email protected] #Together we can do more
The content of the Healthy-Food website is intended to improve, not replace, the contact between the Website User and their doctor. The website is intended for informational and educational purposes only. Before following the specialist knowledge, in particular medical advice, contained on our Website, you must consult a doctor. The Administrator does not bear any consequences resulting from the use of information contained on the Website.