It is the most wide-spread test done by all medical facilities. No treatment is provided without this test. It includes the following markers:

• Hemoglobin,
• Quantity of erythrocytes,
• Colour index,
• Quantity of platelets and leukocytes,
• Leukogram,
• Erythrocyte sedimentation rate (ESR).

Let’s thoroughly dwell on each component.

Hemoglobin is the blood protein which plays the key role in gas exchange. It is connected with oxygen in the lungs transforming into oxyhemoglobin and then moves to the tissues and provides them with oxygen and removes carbon dioxide (carbohemoglobin). Then it goes back to lungs and it is exhaled.Why do we need oxygen so much? Everyone knows that substances may burn only in the presence of oxygen. The same thing occurs in the cells of body. Substances (proteins, fats, carbohydrates) are reprocessed only when they interact with oxygen. It explains why person feels weakness during anaemia (lack of hemoglobin), body lacks fuel.

Quantity of erythrocytes is the number of red blood cells that are in the shape of biconcave disk. Such shape is not accidental, it helps erythrocytes in minimal volume to expand space for hemoglobin contact with oxygen (it’s located on the erythrocyte walls) and to move through narrow capillary tubes by bending. Decrease in the quantity of erythrocytes tells about their increased destruction or insufficient production.

Colour index reflects average quantity of hemoglobin in one erythrocyte. The given test helps doctors to suspect possible cause (there are many of them) of anaemia, from simple iron deficiency in the food to gastric polyp which hinders vitamin B absorption causing malabsorption of iron.

Quantity of platelets is the number of blood cells which participate in the process of coagulation (stopping bleeding). The risk of spontaneous hemorrhages occurs when they decrease in quantity, possible complications during surgery is increased. High platelet count shows «hemoconcentration» and possible thrombus formation.

Quantity of leukocytes is the number of protective cells. The function of leukocytes consists in its fight with all foreign invaders (be it bacteria or plant pollen). For instance, a person cut himself with kitchen knife. Germs got into the wound and on the next day we can see milky purulence on the wound. How did it appear? It’s dead leukocytes which swallowed bacteria and detoxified them. Thereafter elevated leukocytes tell us about the presence of inflammatory reaction in the body.

Leukogram is the correlation of the subspecies of leukocytes: neutrophils, eosinophils, basophils, monocytes and lymphocytes. Each of them fulfills its own function. Neutrophil fights with bacteria, eosinophils fight with helminths and takes part in the immediate hypersensitivity reactions (Hives (Urticaria), Quincke’s edema), basophils participate in delayed hypersensitivity reactions which appear several days after coming into contact with allergen. Increase of this or that cells shows the doctor further algorithm of investigation for precise diagnosing.

Erytrocyte sedimentation rate is the speed (mm/h) of sedimentation of free-floating erythrocytes to the bottom of the tube. Increased ESR indicates that something is not well in the body, from trivial cold and food contamination to the severe cancer diseases. In conclusion we can say that complete blood count is the most available method which allows to evaluate person’s health condition, see acute inflammatory reactions, anaemia, allergy ... However it’s important to remember that to get a complete picture of patient’s health condition we need to evaluate results together with other clinical data.

It’s included to the profile «For children».