Blood is the most important matter of the body, performing regulatory, nutritional, excretory, respiratory and other functions.
50% of blood consists of plasma. This is a multicomponent liquid that includes trace elements, enzymes and hormones. The other 50% belongs to blood cells, each of which has its own unique role.
Any disease, be it inflammatory, oncological, autoimmune or metabolic, affects the qualitative and quantitative composition of the blood. And therefore, the diagnosis of diseases begins with the appointment of a general blood test.
Definition and Purposes of Purpose
CBC (complete blood count) is a laboratory diagnostic method for assessing the condition of the body and searching for the source of pathology. This test can be prescribed by a doctor of any specialty. In what cases is OAC prescribed:
- For prevention during medical examinations. The composition of the blood is relatively constant and rarely goes beyond the normal range in a healthy person. And some diseases may not affect your well-being for a long time, and then a preventive test will become a reason for subsequent examination.
- When the first symptoms of illness appear. Analysis in this case can make it possible to determine the nature of the disease, the degree of intensity of inflammation or an allergic reaction.
- OAC may be re-prescribed to monitor the course of the disease over time. Also to assess the effectiveness of the therapy.
Reasons for deviation from the norm
Factors that may lead to a decrease in the number of red blood cells:
- the formation of anemia in the body;
- insufficient intake of protein and vitamins from food;
- pathologies of the hematopoietic system;
- increased death of cellular elements due to exposure to toxic substances.
Reasons that cause an increase in the level of red blood cells in the blood:
- decreased fluid levels in the body;
- the occurrence of insufficiency in the respiratory and cardiovascular systems;
- pathological disorders in the hematopoietic system.
The main step when detecting changes in the number of red blood cells is to establish the pathology that led to this. To do this, it is recommended to undergo a comprehensive examination.
What indicators are included in the UAC?
The general blood test includes the following indicators: red blood cells, hemoglobin, leukocytes, color index, hematocrit, reticulocytes, platelets, ESR.
The leukocyte formula in some laboratories is signed by default, in some a doctor’s note is required. It includes the following indicators: eosinophils, basophils, band and segmented neutrophils, lymphocytes, monocytes.
Below is a table of norms for a general blood test:
| Index | Laboratory designation | Norma (women) | Norma (men) | Unit |
| Red blood cells | R.B.C. | 3,8-4,5 | 4,4-5,0 | 1012/l |
| Hemoglobin | HGB | 120-140 | 130-160 | g/l |
| Leukocytes | WBC | 4,0-9,0 | 4,0-9,0 | 109/l |
| Color index | CPU | 0,8-1,0 | 0,8-1,0 | |
| Hematocrit | HCT | 35-45 | 39-49 | % |
| Reticulocytes | RET | 0,2-1,2 | 0,2-1,2 | % |
| Platelets | PLT | 170,0-320,0 | 180,0-320,0 | 109/l |
| ESR | ESR | 2-15 | 1-10 | mm/hour |
| Leukocyte formula: | ||||
| Basophils | BAS | 0-1 | 0-1 | % |
| Eosinophils | EO | 0,5-5 | 0,5-5 | % |
| Myelocytes | 0 | 0 | % | |
| Metamyelocytes | 0 | 0 | % | |
| Band neutrophils | NEUT | 1-6 | 1-6 | % |
| Segmented neutrophils | NEUT | 47-67 | 47-67 | % |
| Lymphocytes | LYM | 18-40 | 18-40 | % |
| Monocytes | MON | 3-11 | 3-11 | % |
At some points, the standard blood test for adults differs from that for children.
For example, the norm of hemoglobin in a child is 110-145 g/l, leukocytes 5.0-12.0 109/l, the content of lymphocytes can be in the range of 26-60%. The remaining blood test parameters correspond to the reference values for adults.
By order of the Ministry of Health, in the first year of life, a child’s blood is taken for general analysis 4 times, then at 1 year 6 months, and then annually, starting from two years. Such measures are necessary for the early detection of blood diseases, anemia, and infections.
Interpretation of a general blood test
Below are the most basic indicators of the KBC, their functions in the body, and the reasons for deviations upward or downward.
Red blood cells
These are small elastic cells containing hemoglobin in their cytoplasm. Due to their elasticity, they easily pass through vessels of any caliber. They are produced in the bone marrow, the viability of one cell is about 3-4 months.
Red blood cells perform the following function: they carry oxygen from the lungs to all human tissues and organs, and on the way back from the tissues to the lungs they bring carbon dioxide. All this happens by adding gases to the hemoglobin of the red blood cell.
The norm of red blood cells when deciphering tests is on average from 3.8 to 5.0 1012/l
- An increase in red blood cells in a general blood test is possible with dehydration due to vomiting and diarrhea, diseases of the blood system (erythremia, Vaquez disease), cardiac and respiratory failure.
- their reduction can occur with blood loss, leukemia and lymphomas, congenital hematopoietic defects, hemolytic anemia, oncology, insufficient intake of protein, iron and vitamins.
It should be remembered that the norm of red blood cells, as well as other indicators, may differ in different laboratories. In which, moreover, errors are not excluded. Therefore, a borderline result does not always indicate a serious illness.
Hemoglobin
Hemoglobin is an iron-containing protein found in red blood cells. It is due to this that the function of gas exchange between the lung tissue and all cells of the body is performed. A deviation in hemoglobin levels from the norm can cause a person to feel unwell, weak, and easily fatigued. This is due to a lack of oxygen in organs, including the brain.
The normal hemoglobin content in a general blood test is on average 120-160 g/l, depending on the gender and age of the subject.
- An increase in hemoglobin can occur due to dehydration due to diabetes mellitus, vomiting and diarrhea, due to heart failure, overdose of diuretics, pulmonary failure, heart defects, diseases of the blood and urinary system.
- A decrease in hemoglobin in a general blood test is possible with anemia of various origins and other blood diseases, blood loss, insufficient intake of protein, vitamins, and iron
Leukocytes
These are white blood cells synthesized in the bone marrow. They perform the most important defense function in the body, aimed at foreign objects, infections, and foreign protein molecules. They are also able to dissolve damaged body tissue, which is one of the stages of inflammation. The viability of these cells varies from several hours to several years.
The norm of leukocytes in a general blood test corresponds to 4.0-9.0 109/l.
- An increase in leukocytes in the CBC is possible due to physiological errors (pregnancy, donating blood after meals, heavy physical activity, after vaccinations), inflammatory processes of a systemic or local nature, extensive injuries and burns, active autoimmune diseases, in the postoperative period, with oncology, leukemias and leukemias.
- If, when reading a blood test, leukocytes are reduced, the presence of viral infections, systemic autoimmune diseases, leukemia, radiation sickness, and hypovitaminosis is acceptable. Taking cytostatics and steroids may also affect this.
Color index
The color index (CI) is determined by a calculation method using a special formula. It shows the average concentration of hemoglobin protein (Hb) in one red blood cell.
Normally, the CPU is 0.8-1.0, without units of measurement.
- Its increase may indicate the presence of hyperchromic anemia (vitamin D deficiency).
- A decrease is possible in iron deficiency anemia, posthemorrhagic anemia, leukemia and lymphoma, and chronic organ diseases.
Hematocrit
This is an indicator reflecting the ratio of blood cells (leukocytes, erythrocytes, platelets) to the total blood volume. The analysis is carried out by centrifugation or using analyzers.
Normally, the hematocrit is on average 35-50%.
- An increase may indicate erythremia, respiratory failure, heart failure, dehydration due to diabetes mellitus and diabetes insipidus, diarrhea and vomiting.
- A decrease in hematocrit may be due to anemia, erythrocytopenia, renal failure, pregnancy (third trimester).
Reticulocytes
These are the precursors of red blood cells, their intermediate form. They perform the function of gas exchange, just like red blood cells, but with less efficiency. In a healthy person, reticulocytes, when deciphered, make up 0.2-1.2% of the total number of red blood cells.
- They may be increased during post-hemorrhagic restoration of hematopoiesis, when moving to a mountainous area or when treating anemia.
- Reticulocytes in the general blood test decrease with reticulocytopenia (slow hematopoiesis in the bone marrow, leading to anemia).
Platelets
These are small, flat blood cells that have no color. They perform several important functions - they participate in blood clotting, form platelet thrombus, regulate the tone of the vascular wall, and nourish capillaries.
In a general blood test, the normal platelet count is 180-320 109/l.
- An increase in platelets when deciphering the analysis is possible during splenectomy (removal of the spleen), exacerbation of chronic autoimmune diseases, anemia of various origins, inflammatory processes, in the postoperative period, the third trimester of pregnancy, in oncology, erythremia.
- Platelets in the CBC decrease in hemophilia, drug-induced thrombocytopenia, systemic lupus erythematosus, viral and bacterial infections, aplastic anemia, Evans syndrome, autoimmune thrombocytopenic purpura, and renal vein thrombosis.
ESR
Erythrocyte sedimentation rate (ESR) is an indicator calculated during a laboratory test. Under the influence of anticoagulants, the erythrocyte sedimentation time is calculated, which depends on the protein composition of the plasma.
This is a highly sensitive indicator; normally it averages from 1 to 15 mm per hour.
- It increases during physiological conditions (pregnancy, menstruation), during infectious diseases, malignant neoplasms, systemic autoimmune diseases, kidney diseases, in the postoperative period, during injuries and burns.
- Decreased in astheno-neurotic syndrome, recovery from infection, cachexia, long-term use of glucocorticoids, blood clotting disorders, high concentrations of glucose in the blood, traumatic brain injury, use of NSAIDs, immunosuppressants, antibiotics.
Neutrophils
This is the largest subtype of leukocytes, which, depending on the maturity of the cells, is divided into the following groups - young neutrophils, band neutrophils and segmented neutrophils.
They perform an antimicrobial function, are capable of phagocytosis, and participate in the inflammatory response.
The normal range of neutrophils in a blood test is band 1-6%, segmented 47-67%.
- An increase in neutrophils when decoding a blood test is possible under physiological conditions (sun and temperature exposure, stress, pain, etc.), previous infections, bone marrow diseases, oncology, taking certain medications, ketoacidosis, poisoning with poisons and alcohol, and parasitosis , allergies, hyperglycemia.
- They decrease in the state after chemotherapy, with HIV/AIDS, aplastic anemia, long-term infectious disease, exposure to radiation, deficiency of vitamin B12 and folic acid.
Lymphocytes
This is also a subtype of leukocytes, presented in the form of T lymphocytes, B lymphocytes, K and NK lymphocytes.
All of them participate in acquired immunity, synthesize antibodies, destroy not only foreign, but also their own pathological cells (oncological).
The norm of lymphocytes when deciphered in the CBC is 18-40%
- An increase in the general blood test can occur with viral infections (mononucleosis, viral hepatitis and others), toxoplamosis, blood diseases (chronic and acute lymphocytic leukemia, lymphoma, leukemia), with arsenic, lead poisoning, taking levodopa, narcotic painkillers.
- Lymphocytes decrease in tuberculosis, HIV, blood diseases (lymphogranulomatosis, aplastic anemia), end-stage renal failure, cancer in the terminal stage and during treatment with radiotherapy and chemotherapy, taking glucocorticoids.
Monocytes
This is a type of the largest leukocytes, also synthesized in the bone marrow. They are able to phagocytose (absorb) viruses, bacteria, tumor and parasitic cells. Regulate hematopoietic function and participate in blood clotting.
The normal blood test for monocyte content is 3-11%.
- an increase in monocytes when deciphered indicates viral, bacterial (tuberculosis, syphilis, brucellosis), fungal and parasitic infections, inflammation in the regeneration stage, systemic autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis), leukemia.
- a decrease in monocytes in a blood test is possible during purulent-inflammatory processes, aplastic anemia, in the postoperative or postpartum period, and when taking steroids.
Classification Features
There are two types of erythrocytosis:
- Primary hereditary – refers to genetic pathologies, is rare. The source of the development of the disease is the low susceptibility of oxygen receptors in the kidneys and increased levels of erythropoietin. A sign of the disease is a pronounced loss of strength, attacks of dizziness, a change in the standard shade of the skin and mucous membranes into purple shades, and reduced blood clotting.
- Secondary or acquired - provoked by oxygen starvation of cells, occurs against the background of neoplasms in the liver, kidneys, and respiratory organs.
If the primary form of pathology is ignored, there is a risk of vascular complications, including thrombus formation. The problem is related to changes in the rate of blood clotting.
