Hematic Table: Definition, Objectives, Results, Detectable Diseases and Previous Preparation

Also called a complete blood count, it is one of the most common blood lab studies.

The complete blood count is performed by calculating the elements that are present in the blood.

These analyzes are usually done with the help of special equipment and even the calculations are determined by these machines that analyze the different components of the blood in a very short time.

The values ​​of the concentration of white blood cells, red blood cells and platelets in the blood are important aspects of the complete blood count.

Usually, in a complete blood count the doctor expects to be able to evaluate the general state of the patient’s health through the values ​​reflected in said examination.

It also hopes to detect a series of diseases, which include anemia, infections and leukemia .

With the help of a complete blood count, the levels in which several components are found and several characteristic values ​​present in the blood can be measured.

The blood count lists a number of important values, which usually include the following:

  • The white blood cell or white blood cell counts represent the number of white blood cells in a given volume of blood. Normal values ​​of white blood cell count are in the range of 3.5 to 10.5 billion cells / L.
  • The differential count of white blood cells is composed of several different types such as neutrophils, lymphocytes, monocytes, eosinophils and basophils, which differ in their shape and size. This counting can be done with the help of a computer called automatic differential.
  • In the red cell count or erythrocyte count, the normal range will vary according to the laboratory, but usually the normal levels are located, in men they go from 4.32 to 5.72 trillion cells / L and in women of 3.90 to 5.03 billion cells / L. This count determines the number of red blood cells.
  • The levels of hemoglobin, which is a protein present in red blood cells, are considered normal in men from 13.5 to 17.5 grams / dL, while in women it is 12.0 to 15.5 grams / dL.
  • The amount of hematocrit is the ratio between the volume of red blood cells and the volume of total plasma. The normal levels of Hematocrits are different in each sex, in men it is from 38.8 to 50.0 percent and in women it is from 34.9 to 44.5 percent.
  • The average corpuscular volume is the average volume of erythrocytes or red blood cells. This value is calculated by the red blood cell count. The normal range is between 80 and 100 fl.
  • The mean corpuscular hemoglobin, which is the measure of the mass of hemoglobin, which is contained in a given volume of red blood cells, presents its normal range located between 27 to 32 picograms.
  • The amplitude of the distribution of red blood cells, is a measure of variation in the size and shape of red blood cells and appears, along with other hematimetric indices. The higher numbers indicate a greater variation in size and the normal range goes from 11 to 15.
  • The platelet count shows the amount of platelets found in a given volume of blood. Platelets are not complete cells, they are responsible for the blood coagulation processes. Normal platelet count values ​​vary from 150 to 450 billion / L.
  • The average platelet volume is the amount of platelets in a given volume of blood.


A blood count is a blood test that is performed for a variety of reasons, including:

  • For the preventive control of the individual and frequently monitor the state of general health. The doctor can request a blood picture to perform a routine medical examination, also as part of a preventive health check.
  • For the differential diagnosis of a disease. The doctor may suggest a complete blood count if the patient is experiencing weakness, fatigue, fever, swelling, bruising or the presence of some type of bleeding.
  • A blood picture will show values ​​that can help diagnose the pathology that gives rise to the signs and symptoms that the patient presents. If the doctor suspects the existence of an infection, however slight, with the help of the data presented in the blood picture, you can perform an analysis to confirm that diagnosis.
  • For the control or monitoring of a disease. The doctor can perform a complete blood count to monitor the disease and treatment progress.


In general, some medications can affect the blood cell count, so it must be taken into account that the treatments administered can cause changes in the blood cells at the time of analysis.

A complete blood count does not represent the analysis of a definitive diagnosis, some results may exceed the normal values ​​without it being necessary to follow up.

It is necessary for the doctor to examine the results of the complete blood picture, together with the results of other types of blood tests and complementary studies.

Thus in cases of slight variations in a healthy person, may not be a cause for alarm, but in the case of a patient with oncological treatment , results slightly lower or higher than normal values ​​may indicate the requirement of a modification of the scheme of treatment.

Variations such as the increase or an abnormal reduction in the values, which are evidenced through the complete blood count.

It could give indications of the existence of an undiagnosed disease, which should be evaluated in greater depth through other diagnostic mechanisms.

In cases of results with a large variation with respect to normal values, the doctor should refer the patient to a specialist in blood disorders, a hematologist.

So when results are observed as high values ​​in a white blood cell count, this can mean the presence of an infection in some part of the body.

It may also indicate the presence of a neoplasm underlying malignancy.

A count with low levels of leukocytes or leukopenia may indicate the presence of a problem in the bone marrow or may be related to the administration of some type of medication, such as chemotherapy.

Counts of red blood cells, of hemoglobin and of hematocrit, are intimately related because each of them measures a different aspect of red blood cells.

A low level of red blood cell count or low levels of hemoglobin may suggest anemia, may also indicate diseases of the bone marrow or low levels of oxygen in the blood.

A higher than normal red blood cell count, hemoglobin, or hematocrit may suggest heart disease.

When there is a low level of platelet count, these results may be due to prolonged bleeding or a condition in the production of platelets in the bone marrow.

And if, on the contrary, a high platelet count is observed in the test, this may indicate a bone marrow problem or the presence of some severe inflammation.

Detectable diseases with a complete blood picture

The doctor can recommend or order a complete blood picture when patients show signs of infection, weakness, tiredness, even when they have inflammation, bruises or hemorrhages.

The presence of anomalous results can support the diagnosis of some diseases such as:

  • The infections
  • Inflammations
  • Cancer.
  • To leukemia.
  • Diseases that attack the body’s immune system.
  • Failures in the spinal cord.
  • Abnormal developments of the spinal cord.
  • The anemia
  • Dehydration or loss of fluids in the body.
  • Deficiencies of vitamins and minerals.
  • Thalassemia or abnormal production of red blood cells.
  • The effects of chemotherapy or radiotherapy.
  • The effects of certain antibiotics.
  • The effects of prolonged and even short-term use of certain types of medications.

Previous preparation

In a blood picture only a count of the components of the blood is made, that is why if the patient decides whether or not to keep the fast, this decision will not affect the results of the examination.

If the sample of blood taken is only going to be used for this test, it is not necessary to keep the fast, that is, you can eat and drink everything you want before sampling.

However, with this type of exams it can be requested together with other additional exams, which if they require a minimum fast of eight hours for the subsequent taking of the sample.