Keys to understanding the results of a blood test

There are different types of blood tests depending on the parameters that are evaluated, the most common are the hematological study, in which the blood cells are analyzed, and the biochemical study that measures values ​​such as glycemia, transaminases, bilirubin, etc.

To perform a blood test optimally, a fast prior to blood collection of 10 to 12 hours is necessary. During the test, a healthcare professional cleans the skin, wraps a rubber band around the arm to make the veins swell with blood, and inserts a needle into a vein to draw blood from the venous stream (the volume will depend on the kind of tests that are used). requested, but it is usually 10-20 cc), and introduces the blood sample into a vial or syringe. Some problems that can occur after the extraction are the appearance of blues (hematoma) from the drainage of blood from the vein when the needle is removed or inflammation of the vein (flebilits).

Once the laboratory has analyzed the blood sample and obtained the results, a global study of the values ​​must be made, the diagnosis of which must be based on a general assessment of the person’s health, since an isolated value does not provide solid information to establish disease criteria. Laboratory tests are a tool that the doctor has to guide or support a diagnosis, but by themselves they are not conclusive, since the analytical results must be contrasted with the set of symptoms that the person presents. That is why if we read the results we must be aware that a high value can be punctual and the causes of the alteration are multiple; For this reason, it is usually necessary to repeat the analysis to confirm that the value remains high and to contrast it, both with other tests and with existing symptoms.

How to interpret a blood test (Bigstock)

Parameters to know

When the results of a blood test are read we can routinely find the following parameters in the blood count:

Leukocytes, also known as white blood cells and which are made up of different cells such as neutrophils, lymphocytes, monocytes or eosinophils, are the defense cells against external attacks for elements such as bacteria, viruses, parasites or allergens. They rise with infections and fall when the person’s immune system is low.

-The Red blood cells They contain a protein called hemoglobin, which carries oxygen from the lungs to all parts of the body. The number of red blood cells in the blood is used to determine the presence of conditions such as anemia, dehydration, malnutrition, and leukemia. Other parameters that are evaluated in anemia are ferritin or iron and transferrin deposits, which transports it.

-The platelets, for their part, are responsible for blood clotting, and their alteration determines a tendency to hemorrhage or thrombi.

Regarding the biochemistry of the different organs:

-The function of the kidneys is assessed through substances such as creatinine, a protein that is eliminated by the kidney or urea.

-The bilirubin, pigment that is eliminated by the bile, the alkaline phosphatase waves high transaminases they may indicate liver disease or damage.

-The cholesterol and the triglycerides They are fats that circulate in the blood, associated with a greater risk of suffering from cardiovascular diseases. Within cholesterol, a difference is made between LDL, or bad cholesterol, and HDL, or good cholesterol, which is protective of the cardiovascular system.

-The glucose It is the amount of circulating sugar in the bloodstream and can be found increased in different situations such as diabetes, Cushing’s syndrome or by the consumption of corticosteroids.

-Ions like sodium, potassium or chlorine they are also indicators of the state of our metabolism. Sodium and potassium are usually measured in a blood test, less commonly calcium and chlorine, and, in special circumstances, phosphorus and magnesium. They allow to identify problems in the hydro-electrolyte balance of the body, essential for the maintenance of important functions, such as the functioning of the heart, muscles or the nervous system.