Decoding of a general blood test in children

Decryption of the result obtained after the study should be carried out by an experienced doctor. Any indicator is of great importance for the normal activity of the whole organism, and the occurrence of any deviation in blood parameters can affect the activity of organs and their systems.

Among the main data reflected in the detailed blood test in children, the following indicators are noted:

  1. Hemoglobin. Responsible for transporting oxygen by red blood cells. The concentration of hemoglobin affects the supply of oxygen to tissues, cells, the development of the child, the functionality of the heart.
  2. Red blood cells. Carry oxygen through the body, carry out the removal of carbon dioxide. Thanks to these blood cells, the blood has a red color, and any change in color can affect the well-being of the child. What other indicators of a detailed blood test in children exist?
  3. White blood cells. These blood cells are responsible for the activity of the immune system, their detection in a blood sample may indicate the presence of an inflammatory process in the child’s body. Specialists distinguish several varieties of white blood cells, each of which is responsible for the normal activity of the child’s body.
  4. Reticulocytes. Their concentration affects the work of the kidneys and bone marrow.
  5. Matured segmented neutrophils. They prevent the penetration of parasites and bacilli into the body.
  6. Neutrophils are unripe stabs. An increase in their concentration may indicate an infectious pathology, bacterial infection, and an inflammatory process.
  7. Platelets. Responsible for the coagulation process.
  8. Monocytes. These blood cells kill dead cells, as well as bacteria. With an increase in the concentration of monocytes, one can judge the presence of a protracted pathological disorder in the body.
  9. ESR (rate at which erythrocyte sedimentation occurs). An increase in this indicator indicates the presence of an inflammatory focus.
  10. Eosinophils. They are a type of white blood cells that can block the manifestations of allergies, inflammation, and the growth of malignant structures.
  11. Basophils. Responsible for allergic manifestations, blood coagulation.
  12. Lymphocytes These cells destroy antigens, and an increase in their concentration indicates that the body resists viral infection.

To obtain a reliable result, you should follow the doctor’s recommendations. In this case, the pediatrician will be able to decrypt the analysis and recommend timely therapy, thereby preventing the development of serious consequences.

Why are there deviations from the norm in decoding a detailed blood test in children?

During a detailed analysis, qualitative and quantitative parameters of blood elements are taken into account. For research, as a rule, capillary blood is used.

What does the decoding of a detailed general blood test mean? The red blood group assesses the quality, the number of red blood cells and all their indices. The norm of almost all indicators depends on the gender of the baby, and in addition, as already noted, on age.

Each laboratory uses its own reference values, which are prescribed in the column of the norm of a detailed blood test in children. They may differ in different laboratories, but this difference will be insignificant. Normal indicators depend on the methods of counting blood elements, as well as the equipment used. The doctor must take this fact into account when decoding the analysis. Norms are presented in the table.

The group of absolute indicators includes indicators of hemoglobin concentration, qualitative, quantitative characteristics of red blood cells. The pediatrician focuses on both indicators when decoding a detailed general blood test and determining the diagnosis.

Hemoglobin is a protein that is responsible for the binding of oxygen molecules and its transportation to tissues, organs, systems. This protein easily combines with oxygen and just as easily releases it. The transport characteristics of the blood and, accordingly, the activity of the brain, heart, and the development of the child directly depend on the saturation of the blood with hemoglobin.

By about six months of age, gender differences in hemoglobin levels become noticeable:

  1. The norm of hemoglobin for girls of 0,5-2 years is considered to be a concentration of 106-148 grams / liter. For boys of this age, the norm is as follows – 114-144 grams / liter.
  2. The norm of hemoglobin for girls 3-6 years old is considered to be an indicator of 102-142 grams / liter. For boys of the same age, the norm is as follows – 140-140 grams / liter.

An increase in hemoglobin concentration in the general detailed blood test in a child is observed with pulmonary failure, heart dysfunction, pathological changes in the kidneys, diabetes, blood diseases, dehydration.

Red blood cells are shaped elements, the main task of which is to transport hemoglobin, the relationship with oxygen molecules. These elements are present in blood in large quantities. Deviations from normal values ​​- evidence of impaired regenerative function of red blood or too much loss of it.

When assessing the state of red blood, laboratory assistants take into account the number of red blood cells and their shape (normally they have a biconcave shape), as well as their level of maturity. No less important are the following indices: average hemoglobin content in an individual red blood cell, average erythrocyte volume (MCS and MSN, respectively).

Reticulocytes are immature red blood cells. Sometimes the absolute value of reticulocytes is calculated in laboratories, but their percentage is usually analyzed in relation to the total number of red blood cells. An increased content of reticulocytes indicates an accelerated breakdown of red blood cells.

Red blood cell deficiency occurs with leukemia and other oncological pathologies, hemolysis, genetic fermentopathies, large blood loss, nutritional anemia. An excess of red blood cells may indicate a fluid deficiency, active loss of fluid, serious pathology in the kidneys, heart, narrowing of the renal artery, erythremia.

Also, when deciphering the results of a detailed blood test, relative indicators are also taken into account.

An important relative indicator is hematocrit, which makes it possible to estimate the ratio of the number of shaped elements to the total plasma volume. That is, hematocrit actually reflects the density of blood.

Hematocrit can decrease with renal failure, anemia, and increase with dehydration due to extensive burns, vomiting, diarrhea, blood loss, diabetes.

Taking the biomaterial from a child can be carried out in various ways, due to his age or characteristics of the body. In some laboratories, for clinical analysis, capillary blood, that is, from the finger, will be required, while in others it will be venous. The first option of the fence is used most often, since it is simple.

However, at the same time, blood taken from the finger, and in newborns from the heel, coagulates much faster than venous. This property leads to the formation of microbunches, which in turn can distort the results of the study. Therefore, venous blood is considered more suitable for diagnosis, but only a nurse with extensive experience can take blood from a child painlessly.

Regardless of where the blood is taken from – the puncture site is pre-lubricated with a swab moistened with alcohol. If a capillary biomaterial is taken, then a soft tissue puncture of the fingertip, most often anonymous, is done with a scarifier (special tool). Then, gently squeezing a finger, collect a few drops of blood in a test tube.

If there is a need to take venous blood from a child, then the laboratory assistant places a rubber band on the forearm to the baby to partially reduce its outflow from the limb. After that, finding a vein becomes easier.

In the vast majority of cases, an ulnar vein is used for puncture and blood collection. The required biomaterial is collected using a syringe, test tube or a vacuum tuner specially created for such purposes.

The principle of capillary blood sampling in children

In both cases, this procedure can be associated with a certain stress for a small patient, since a puncture of the skin, although insignificant, still causes pain. Therefore, much depends on the actions of the laboratory employee and the parents themselves.

If the child already understands the purpose of visiting the clinic, then he should be able to explain why the analysis is necessary and how to behave during the procedure, and during the fence itself try to distract with some interesting story.

The very first blood test is performed on a newborn in the hospital, and then during routine checks at 3 months and a year. If the baby is healthy and does not bother anything, then a general blood test should be done once a year in the process of a general medical examination.

The form of a detailed analysis looks like a table that contains blood counts in one column, and in the other, respectively, for comparison, reference values ​​for children of different ages.

This is very convenient, and even a person not familiar with medicine can see deviations in the table, if, of course, such are defined. So, a children’s advanced KLA without fail includes the following list of blood characteristics.

  1. Hemoglobin (Hb)
  2. Red blood cells (RBC)
  3. Reticulocytes (RTC)
  4. To start, let’s remember a few important things
  5. What to do if there are deviations in the general blood test of the child?
  6. Basophils
  7. Hemoglobin
  8. How to prepare for a general blood test
  9. Who is prescribed a general blood test
  10. Platelet concentration in the blood
  11. leukocytes
  12. Lymphocytes
  13. Monocytes
  14. Sedimentation rate of erythrocytes
  15. Eosinophils
  16. Instead of a conclusion
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Hemoglobin (Hb)

A complex iron-containing protein, as well as an important component of red blood cells, having the ability to attach oxygen and transport it to all body tissues. For a newborn in the first three days of life, 145-225 g / l is considered the norm, by 3-6 months, the values ​​fall to 95-135 g / l. Gradually, in the process of a child’s growth, hemoglobin norms approach the ratios of adults – 120-160 g / l.

Red blood cells (RBC)

These are red blood cells, the main duty of which is to ensure the transfer of hemoglobin through the bloodstream to various organs. Recently born babies often have an increased content of red blood cells, which is equated to the norm – 3,9-6 million / μl. In children from one year to 12 years old, reference values ​​are considered to be 3,8-5,1, which differ little from the norms of adults.

This ratio is the average concentration of Hb in the blood. It is calculated using a special formula and directly depends on the number of red blood cells and the content of hemoglobin. Normally, in a child’s blood, the coefficient obtained should not leave the interval of 0,8-1,05.

Reticulocytes (RTC)

To start, let’s remember a few important things

First: don’t need to take tests “just like that”. There must always be a good reason for this — illness or screening period. Every skin puncture is stress for a child, especially a small one. Any stress slows the development of the baby and leads to metabolic disorders, albeit for a short time.

Second: the test results are just numbers that tell you and the doctor that on such and such a day and time, the baby’s blood looked that way. All. Now, perhaps, everything is completely wrong in the baby’s blood. Blood is a liquid that does not have a constant composition. It changes every minute, if not a second. Seeing a result that is beyond the normal range, do not panic right away.

Perhaps this is an accident or a response to some short-term impact. For example, the child was very afraid to donate blood and cried. As a result, he developed a lot of stress hormones that affected the overall composition of the blood. Or the day before, the baby ate a decent portion of sweet, or maybe fat.

Third: take a blood sample as comfortable as possible for the child. That there was no fright, tears and screams. Prepare it for this event, give as an example the courage of friends and favorite movie heroes, relatives. Then the chances of the reliability of the results will be greater.

Now let’s get acquainted with the indicators of a clinical blood test.

What to do if there are deviations in the general blood test of the child?

Blood sampling for general analysis is carried out from capillary blood, i.e. from the finger, where the small external vessels are located. In infants, blood is taken from the toe or from the heel, because the fingers on their hands are very tiny. For sampling, it is necessary to have a sterile scarifier, cotton wool, alcohol (or an alcohol wipe), rubber gloves, and recently in the laboratory they require a tube for blood sampling.

There are times when a child is prescribed both a general and a biochemical blood test. In this case, the laboratory assistant can take blood from a vein and send a certain amount of it for general analysis.

To obtain a result, a drop of blood is placed on a glass slide, rubbed with another glass of this kind and the laboratory assistant examines the smear obtained under a microscope. In a general blood test, indicators are determined that affect its composition: red blood cells, hemoglobin, hematocrit, platelets, white blood cells, nuclear bacilli and others.

The laboratory assistant counts the corresponding blood cells, determines their shape, size, maturity, the presence or absence of various particles in them. One of the important indicators of a clinical blood test is the erythrocyte sedimentation rate (ESR) or the erythrocyte sedimentation reaction (ROE). In decoding, this indicator can be indicated both so and so, it does not matter. It means the sedimentation rate of sediment from red blood cells in a test tube per hour.

  • Not a single indicator is considered in isolation!
  • The doctor analyzes all the indicators in a complex and what seems to you pathology may turn out to be the norm for your child.
  • Analysis results from a vein differ from a blood test taken from a finger.
  • Adult analysis results differ from those of children.
  • Children of different ages have different norms.
  • Children of different complexion have different results.
  • On one blood test no conclusions are made!
  • A blood test is an auxiliary diagnostic method, the diagnosis is established only by the doctor on the basis of a comprehensive examination, examination and questioning.

Did you know that in some laboratories queues are specially arranged for 20 minutes so that the children sit quietly and the tests are more reliable?


Basophils are immune cells, the number of which is small in both adults and children. The normal content of basophils is considered to be 0-0,5, which is about 1%. Large amounts of basophils are found in compounds involved in the inflammation process. Thus, an increase in their concentration indicates the presence of a delayed immunological reaction.

Basophils belong to leukocytes and play an important role in the human body. They are the first to react to the appearance of strangers, trying, if not to neutralize them, then at least stop them until “reinforcements” arrive. Basophils “pounce” on allergens and poisons, go to places of inflammatory reaction, helping to restore blood flow.

Normally, the number of basophils in children ranges from 0,5 to 1% or, in absolute numbers, 0,01 billion / l.


Hemoglobin captures from the lungs and carries oxygen to human organs and tissues. Consists of protein and iron. If iron is not enough, they talk about iron deficiency anemia and record a decrease in hemoglobin in the blood.

Table No. 1: Norms of hemoglobin in children of different ages according to WHO

The World Health Organization considers normal a fairly wide range of data for children even of the same age.

In breast-fed infants, hemoglobin is usually lower than their artificial peers. The nature of this phenomenon has not been fully studied, however, such a decrease in the level of hemoglobin in the blood in infants is no longer considered pathology.

How to prepare for a general blood test

There are a huge number of different analyzes, usually biochemical, that are taken from a vein. These tests are always taken standardly: in the morning and on an empty stomach.

There is a tendency that after eating or after a long period after waking up the level of red blood cells and other components in the blood is higher or lower than normal.

It is believed that the optimal condition for taking tests is a break between meals from 8 to 12 hours. It is clear that it is easier to do this in the morning, when the child just woke up. But for a clinical blood test, these rules are not fundamental. This means that you can donate blood for a general analysis at any time.

Nevertheless, in polyclinics it is customary to take tests in the morning at strictly allotted hours, both biochemical and general. This is due to the fact that the staff of state medical institutions, and sometimes self-financing clinics, are subject to a strict schedule.

In order to save money, the staff is reduced to a minimum and in order to manage to process the results, the staff is forced to work in a similar mode: in the morning – a sampling of analyzes, in the afternoon – their processing.

In situations where the results of a general analysis are urgently needed, the doctor will not be guided by the patient’s stomach condition, its biorhythms and other factors. In addition, at the request of a doctor, the results can be ready within 60 minutes, which will facilitate the diagnosis of the child and increase the effectiveness of medical appointments.

Who is prescribed a general blood test

Indications for a general blood test can be either any malaise of the child, or a serious illness, with an unexplained cause and diagnosis. A clinical blood test is prescribed in the following cases:

  • the child has complaints that cannot be explained from a medical point of view;
  • to determine the general condition and severity of the patient;
  • a long course of the disease, which at first glance should not have caused such a long treatment;
  • with a secondary disease, with complications;
  • examination of children before surgical procedures;
  • routine examination of children registered in the dispensary (medical examination);
  • preventive examination of healthy children, as well as when applying for school, kindergarten, etc.
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It should take into account the material capabilities of state clinics, which can do a limited number of tests per week. Therefore, doctors prescribe a general blood test for children in exceptional cases.

Platelet concentration in the blood

Platelets also belong to red blood cells. They look like small plates. Their main goal is normal blood coagulation.

Table No. 6: platelet count in children

  • Thrombocytopenia – when platelets in the blood are less than normal;
  • Thrombocytosis – if more than normal.

In modern laboratories, platelet indices are also determined.

To obtain the full results of a comprehensive study of blood samples, it is important to take into account such an indicator as the concentration of platelets in the blood. Platelets are small cells that do not have nuclei and shapes and are directly involved in the process of blood coagulation. Normally, there are a lot of them in the blood – 180-320 in 109 g / l.:

  1. Children of the first day of life – 180-490.
  2. Infants – 180-400.
  3. From 1 to 6 years – 160-390.
  4. From 7 to 12 years old – 160-380.
  5. From 13 to 15 years – 160-360.

Thrombocytosis may result from the development of cancer, erythremia, anemia, splenectomy, profuse blood loss, and inflammatory reactions.

Thrombocytopenia can develop as a result of toxoplasmosis, malaria, rickettsiosis, hemophilia, and some varieties of anemia.


White blood cells are a whole group of cells that differ in shape, size and in their properties. All of them protect our body from infections caused by bacteria, viruses and other foreign agents. Therefore, the total number of white blood cells has a significant diagnostic value.

Simplistically, leukocytes can be considered soldiers standing to guard the borders of our body. Preventing the penetration of the enemy, they die, existing only 10-12 days. The body constantly makes up for these losses, producing new cells in the bone marrow, spleen, lymph nodes and tonsils.

In the analyzes, white blood cells are designated as:

White blood cells are heterogeneous, so doctors always take into account not only their number, but also indicators of the so-called white blood cell formula, in which they distinguish: eosinophils, neutrophils, basophils, monocytes and lymphocytes.


Lymphocytes are also a type of white blood cell. There are many of them and they are engaged in several things at once:

  1. participate in the synthesis of antibodies that quickly cope with the infection;
  2. destroy strangers and their bad (inferior, mutated) cells;
  3. accumulate in places of injuries: wounds and cuts to block pathogens.

Lymphocytes are divided into:

  • B-lymphocytes, which, in contact with microbes, memorize them and form the very specific immunity that a child can develop by having been ill with a certain infection or vaccinated against it.
  • T-lymphocytes are involved in the direct destruction of abnormal or foreign cells:
    • T-killers destroy harmful cells;
    • T-helpers help T-killers;
    • T-suppressors ensure that their own healthy cells are not accidentally damaged.

Lymphocytes in laboratory analysis are designated as:

Lymphocytes are counted as a percentage of the total number of leukocytes, but sometimes absolute numbers can also be seen in the analyzes. In this case, the interval is considered to be the norm from 1 to 4 billion per liter.

You can calculate the absolute number of lymphocytes yourself (if you are concerned about the fact that the percentage is higher than the age norm). For this there is a formula: LK x LF% = LF. That is, you look – how much the child has in the analysis of white blood cells and multiply this number by the percentage of lymphocytes (multiply by the number of lymphocytes and divide by 100), you get how many lymphocytes in absolute numbers the child has now. And if this value fits into the norm, you don’t have to worry much.

Example: a child has 4,0 billion leukocytes and 40% of lymphocytes. So we multiply 4 billion by 40 and divide by 100, it turns out 1,6 billion. This fits into the norm.

What does it mean if lymphocytes are more or less than normal?

Atypical lymphocytes may be indicated in the analysis. Normally, they should be no more than 6%.

The second largest group of white blood cells are lymphocytes. Their tasks include humoral immune responses, cellular immunity. Normal lymphocyte counts are also dependent on the age of the child and are as follows:

  • Up to 3 days – 15-35.
  • Up to 14 days – 22-55.
  • 2 weeks-1 year – 45-70.
  • 1-2 years – 37-60.
  • 2-5 years old – 33-55.
  • 6-9 years old – 30-50.
  • 9-11 years old – 30-46.
  • 12-15 years old – 30-40.

Lymphocytosis (increased concentration of lymphocytes) develops with toxoplasmosis, viral infections, acute respiratory viral infections, and blood diseases. Lymphocytopenia can be the result of radio wave therapy, chemotherapy, renal failure, some pathologies of the blood, AIDS, tuberculosis, terminal stages of cancer.


Monocytes are gigantic immune cells. If you rely on a quantitative ratio, then they contain a little in the blood. Monocytes – a kind of radar of the body, responsible for the recognition of foreign proteins that enter the bloodstream.

In children, normal monocyte counts are as follows:

  • 0-3 days – 3-12;
  • from 3 to 14 days – 5-15;
  • 14 days-1 year – 4-10;
  • from 1 to 2 years old – 3-10;
  • from 2 years – 3-9.

Monocytopenia accompanies some types of leukemia, occurs after surgery, on the background of phlegmon, abscess, hormone therapy, osteomyelitis. Monocytosis can occur with arthritis, leukemia, myeloma, sarcoidosis, brucellosis, syphilis, tuberculosis, colitis, after an infectious disease.

Monocytes are also representatives of the white blood cell group. These are very interesting cells that live in the blood for only 2-3 days, and then turn into tissue macrophages, where they acquire the ability to move independently, resembling large amoeba. They do not just move, but, like wipers, cleanse tissues of everything that is unnecessary and alien – damaged and degenerated (tumor) cells, bacteria and viruses. And they also produce interferon – a tool that helps to cope with pathogens of various diseases.

In analyzes, monocytes are designated as:

Most often, the results of the analyzes are given as a percentage.

The reasons for the increase and decrease in monocytes in children

Sedimentation rate of erythrocytes

Red blood cells – human blood cells (red blood cells), reminiscent of strongly flattened balls on both sides. They contain the very hemoglobin that carries oxygen.

Table No. 2: Red blood cell count is normal

From two months to about two years, the content of red blood cells is slightly lower due to the characteristics of the child’s body.

A very simple test that almost all laboratories use. Blood is collected in a narrow tube, which is installed vertically. Almost immediately, the liquid is divided into two fractions: heavy red blood cells go down. How many millimeters they will fall in an hour – such a result will be written in the analysis.

ESR standards in children

ESR: causes of lowering and increasing in children


Eosinophils are shaped elements involved in the formation of humoral immunity. They fight toxins that are released in the body during any poisoning or cancer intoxication. Normal eosinophil concentrations are dependent on the age of the child:

  • Up to 14 days – 1-6.
  • from 14 days to 1 year – 1-5.
  • from 1 to 2 years – 1-7.
  • from 2 to 5 years – 1-6.
  • from 6 to 15 years – 1-5.

The lack of eosinophils may be due to an inflammatory, purulent process, intoxication with salts of heavy metals. Redundancy can indicate a variety of pathologies – from allergies to cancer.

Eosinophils are a type of white blood cell, according to which doctors judge the presence or absence of an allergic reaction in a child. Eosinophils are part of the leukocyte formula, and therefore they are considered as a percentage. That is, how many percent of white blood cells (of all) are eosinophils.

Norms of eosinophils in the blood of a child

Usually, doctors do not consider eosinophils to units, but reason like this:

  • up to 5 – normal;
  • 5-10 – doubtful;
  • above 10 – there is an allergy.

What diseases increase eosinophils in a child?

Instead of a conclusion

Thus, the decoding of the norms of the general detailed blood test is an integral part of absolutely any examination. However, just studying the results obtained is not enough. The doctor will have to compare them with the patient’s complaints and clinical manifestations. Only such a comprehensive approach will allow us to correctly diagnose the cause of deviations in the analyzes and prescribe effective and timely therapy to prevent the development of serious consequences. Therefore, the decoding of a detailed blood test in children is only the first step in the diagnosis and subsequent treatment of possible diseases.

With a viral and bacterial infection in the body, completely different things happen according to the leukocyte formula. Only by the results of KLA it is possible to determine what type of infection is in the body of the child, and when it is time to give antibiotics.

Svetlana Borszavich

General practitioner, cardiologist, with active work in therapy, gastroenterology, cardiology, rheumatology, immunology with allergology.
Fluent in general clinical methods for the diagnosis and treatment of heart disease, as well as electrocardiography, echocardiography, monitoring of cholera on an ECG and daily monitoring of blood pressure.
The treatment complex developed by the author significantly helps with cerebrovascular injuries and metabolic disorders in the brain and vascular diseases: hypertension and complications caused by diabetes.
The author is a member of the European Society of Therapists, a regular participant in scientific conferences and congresses in the field of cardiology and general medicine. She has repeatedly participated in a research program at a private university in Japan in the field of reconstructive medicine.