Blood test

, medical expert
Last reviewed: 20.11.2021

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A blood test is the most common method of research, without which modern diagnostics are not possible. Different types and methods of analytical blood research help modern medicine to quickly and accurately identify hundreds of thousands of ailments.

The blood test, as a rule, must be taken in the early morning, preferably on an empty stomach. This is explained quite simply. Blood flow in the human body circulates incessantly, daily and every minute. Blood is extremely susceptible to the influence of many factors, both external and internal. Just internal factors and will be the subject of study in the analysis, in order for the clinical picture to be more clear, external factors are, as far as possible, excluded. The composition of blood can affect both food, and stress, and even physical fatigue.

Blood analysis and types of analytical studies: 

  • Clinical, which is often denoted by the abbreviation OAK - a common blood test; 
  • Biochemical; 
  • Studies of hormones; 
  • Analysis that determines allergens.

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The analysis of a blood general, clinical

The analysis of the blood is general, the clinical is the most frequently prescribed analysis, which is surely familiar to many of us. In this study, quantitative indicators of the main elements of the blood are determined. The first on the list is hemoglobin - an indicator of blood saturation an important element that provides many functions of the body - oxygen. Hemoglobin is part of the erythrocytes, which are also identified in the UAC.

The definition of hematocrit helps to understand how many red blood cells are in a percentage of a given amount of blood. In addition, an important leukocyte index is indicated, showing the presence of intoxication in the body caused by inflammatory processes or infection. The determination of ESR (at which rate the erythrocytes settle in a special laboratory tube) helps to identify the inflammatory process when it is so hidden that it can not be determined by counting the number of white blood cells. Thrombocytes, the smallest cells of the blood flow, which are responsible for the processes of blood coagulation, are counted .

It is these small blood cells that protect a person from excessive blood loss, sticking together and transforming into clots. Clinical analysis is conducted to determine, specify the following conditions and disease: 

  • Anemia; 
  • Exhaustion, chronic weakness; 
  • The appearance of bruises, bruises without objective causes (injuries, bruises); 
  • Blood loss; 
  • Infectious diseases; 
  • Possible diseases of the hematopoietic system; 
  • Monitoring the effectiveness of drug therapy; 
  • Condition before surgery. 

Blood chemistry

Biochemical research determines the enzyme indices, as well as the amount of lipids, proteins, certain types of pigments (bilirubin), vitamins and nitrogenous substances. Biochemistry shows the malfunctioning of many organs, such as the liver, urino-genital organs, kidneys. With the help of this analysis, rheumatism, changes in the water-salt balance, and the number of trace elements can be detected. In addition to specifying information about the diagnosis itself, biochemical research helps to determine the stage, severity of the disease. This type of analysis is performed with the help of blood sampling from the vein. 

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Blood test for hormones

The blood test, which determines the level and ratio of hormones, helps assess the condition of the adrenal gland, the thyroid gland. Many endocrine diseases require such a study. 

trusted-source[13], [14], [15], [16], [17], [18], [19]

Blood test for allergens

The definition of allergens helps to identify the real "enemy" - a harmful agent that provokes the immune system to an aggressive reaction. This analysis determines the level of specific IgE immunoglobulins, which are markers of allergic reactions. 

trusted-source[20], [21], [22]

Blood test for oncomarkers

The definition of oncomarkers helps to identify proteins that form in neoplasms. Oncomarkers determine the degree of severity of the process, and can also help to clarify - a benign this formation or it already passes into a stage that threatens the life of the patient.

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Blood test, which determines the level of vitamins in the body

This study is appointed when there are all signs of vitamin deficiency and micronutrient deficiencies in the body. Also using this analysis, hypervitaminosis is determined, which can arise as a result of uncontrolled self-intake of certain vitamins, especially vitamin A and C. In the laboratory, a biochemical blood test is performed to determine concomitantly the concentrations of B12 vitamins, folic acid and the levels of iron, potassium, calcium, sodium. Other groups of vitamins (C, B1, D, E, B5) are not subject to precise determination, they are computed comprehensively 

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Blood test for medicines

A blood test to determine the concentration of drugs in the body helps to monitor the pharmacokinetics in a medical course of treatment. Drug monitoring is carried out using a microbiological or spectrophotometric method. Such information allows to carry out therapeutic control over the actions of prescribed medications, to reveal their inefficiency and to replace them with more effective ones in due time. 

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Blood test for drugs

The blood test for the definition of narcotic substances is one of many parts in forensic medicine. 

Laboratory blood tests for the presence of drugs are much inferior in informative analysis of urine, but with the help of blood can determine the multiplicity and duration of reception of chemicals. Such an analysis can detect traces of drugs used 3-4 months ago, until the time of the study. Quarterly test is intended to establish the very fact of consumption, it well identifies even small traces of amphetamines, cannabinoids, opiates, which were introduced into the body long before the analysis.

The blood test is done quickly enough, the time to process its results depends on the type and method of the study. The fastest is considered UAC, as well as biochemical analysis. Processing of all other species can take from two to seven days. The decryption is entered in a special form, where there are fixed rates and detected blood indicators. The ratio of the norm and the deviation from it allows the doctor to specify the diagnosis and more accurately build therapeutic measures. It should be taken into account that an independent interpretation of the analysis can cause a false alarm. Norms of indicators depend on the age of the patient, and the results are treated in conjunction with other factors - visual examination, comparison with urinalysis and other types of research. Therefore, it is better to provide the analysis to the specialist.

trusted-source[37], [38], [39], [40]

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