Biochemical Blood Test: What Is It, Indicators

2024 Author: Rachel Wainwright | [email protected]. Last modified: 2024-01-15 19:51

Biochemical blood test: norm and table for decoding results

The content of the article:

Preparation for the delivery of a biochemical blood test
Norms of indicators of biochemical blood test

Decoding of indicators of biochemical blood test

Total protein
Glucose
Total cholesterol
Total bilirubin
Alanine aminotransferase
Aspartate aminotransferase
Urea
Creatinine
Alpha amylase
Calcium
Iron
Magnesium

A biochemical blood test (blood biochemistry) is a complex of laboratory tests that allows you to assess the state of internal organs and body systems.

The results of biochemical studies are of great importance for the diagnosis of many pathological processes (including at early stages) and the selection of adequate treatment.

A biochemical blood test is one of the basic studies, which is prescribed for most diseases of internal organs, as well as for preventive purposes

In addition to blood tests, in some cases, biochemical analysis of other biological fluids of the patient is carried out.

For preventive purposes, this analysis is recommended at least once a year. In the presence of chronic diseases of the liver, kidneys, the need for long-term use of drugs, the presence of occupational hazards, a biochemical blood test in adults is carried out 2-4 times a year.

Preparation for the delivery of a biochemical blood test

Before taking the analysis, it is advisable to consult with a doctor who will explain in detail what a biochemical blood test is, for what purpose it is carried out and what it shows, and then decipher the results of the study for each parameter.

For biochemical research, venous blood is required (blood serum is used). Blood sampling is performed in the morning before 11:00, on an empty stomach, at least eight hours should pass from the last meal. It is not recommended to donate blood after physiotherapy and X-ray examination. On the eve of blood sampling, it is necessary to exclude the use of fatty and fried foods, coffee, strong tea and alcoholic beverages. Physical and mental stress should be avoided. If it is necessary to repeat studies, it is recommended to take tests in the same laboratory with the most similar preparation conditions.

Norms of indicators of biochemical blood test

A biochemical blood test is usually carried out during a comprehensive examination of a patient, any change in indicators indicates certain processes occurring in the body. A standard panel of biochemical tests (complete biochemical analysis) or a study of specific indicators can be assigned, depending on the purpose of the study and the existing clinical picture. The standards of the studied indicator for men and women may be general or differ.

Normal values of indicators of biochemical research are presented in the table. Norms and units of measurement may vary from laboratory to laboratory.

Norms of indicators of biochemical blood test:

Index	Reference values
Total protein	65–85 g / l
Glucose	4-6 mmol / l
Total cholesterol	3.5-6.5 mmol / L
Total bilirubin	3.4–20.5 μmol / L
Alanine aminotransferase (ALT, ALT)	Men - up to 41 U / l Women - up to 31 E / l
Aspartate aminotransferase (AST, AsAT)	Men - up to 47 U / l Women - up to 31 E / l
Urea	2.5-8.3 mmol / L
Creatinine	Men - 62-115 μmol / l Women - 53–97 μmol / l
Alpha amylase	25–125 U / l
Calcium	2.15-2.5 mmol / l
Iron	Men - 10.7-28.6 μmol / L Women - 7.2-25.9 μmol / L
Magnesium	0.65-1.05 mmol / l

Decoding of indicators of biochemical blood test

Total protein

Total protein is an important indicator of protein metabolism in the body and is the total content of albumin and globulins in the blood serum. Human blood proteins take part in maintaining osmotic pressure and blood pH, in the process of blood clotting, transfer steroid hormones, lipids, bilirubin.

An increase in the concentration of total protein occurs with dehydration of the body (with extensive burns, persistent vomiting, diarrhea, etc.). An increase in this indicator in some cases indicates the presence in the body of an infectious process, autoimmune diseases, malignant neoplasms with hyperproduction of pathological proteins.

A decrease in total protein can be a sign of insufficient intake of protein from food, excessive physical exertion, injury, prolonged fever, chronic bleeding, anemia, thyrotoxicosis, liver, kidney, intestinal diseases, and malignant tumors.

Physiological decrease in the level of total protein is observed in children of the first year of life, pregnant and breastfeeding women, as well as in patients who are on prolonged bed rest.

Glucose

Glucose is an organic compound, the main participant in carbohydrate metabolism. More than 50% of the energy the human body receives in the oxidation reactions of glucose, which comes from food and is produced by the cells of the body from lactate, amino acids, etc. Excess glucose is deposited in the liver in the form of glycogen.

Measurement of blood glucose concentration plays an important role in the diagnosis of diabetes mellitus. The study is recommended to be carried out regularly for all people over 45 years old, since a change in this indicator with the development of diabetes occurs earlier than the first clinical signs of the disease appear. Determination of the glucose level is used to detect pathologies of the thyroid gland, adrenal glands, pituitary gland, the causes of obesity and pregnancy complications.

An increase in glucose concentration (hyperglycemia) is observed in diabetes mellitus, impaired glucose tolerance, acute and chronic pancreatitis, myocardial infarction, cerebral hemorrhage, endocrine diseases (gigantism, acromegaly, pheochromocytoma, cystic fibrosis, thyrotoxicosis of a number of kidneys and chronic liver diseases), medicines (caffeine, glucocorticosteroids, estrogens, thiazides), as well as during pregnancy.

Physiological hyperglycemia is possible with physical and / or mental stress, stressful situations.

A decrease in blood glucose (hypoglycemia) can be a sign of pancreatic neoplasms, severe liver damage (hepatitis, cirrhosis, tumor), endocrine diseases (hypopituitarism, Addison's disease, adrenogenital syndrome), taking certain drugs (amphetamine, anabolic steroids, insulin, antihistamines). Hypoglycemia accompanies poisoning with chloroform, arsenic, alcohol intoxication, in addition, it is characteristic of premature babies.

Total cholesterol

Total cholesterol (cholesterol) is a component of fat metabolism that is involved in the production of sex hormones, vitamin D and the construction of cell membranes.

In addition to total cholesterol, when conducting a biochemical blood test, the concentration of high density lipoproteins, low density lipoproteins and triglycerides is usually determined. The combination of these indicators is called a lipid profile. Depending on the purpose of the study, during the biochemical analysis, all indicators of the lipid profile or some of them can be determined.

An increase in total cholesterol is a risk factor for the development of atherosclerosis and cardiovascular pathologies. An increase in blood cholesterol is observed in diseases of the liver, kidneys, pancreas, diabetes mellitus, hypothyroidism, gout, chronic alcoholism, obesity, as well as eating large amounts of fats and carbohydrates.

A decrease in total cholesterol occurs with impaired absorption in the intestine, liver pathologies, rheumatoid arthritis, acute infectious diseases, hyperthyroidism.

Total bilirubin

Bilirubin is a bile pigment that is a breakdown product of hemoglobin. Bilirubin is produced in the spleen and bone marrow during the breakdown of erythrocytes and is a component of bile.

Total bilirubin is the sum of direct and indirect bilirubin. In some cases, in addition to total bilirubin, it is required to determine its fractions.

Determination of the concentration of bilirubin is of diagnostic value in case of suspected hepatitis, cirrhosis, liver neoplasms, cholelithiasis, hemolytic anemia, vitamin B ₁₂ deficiency.

An increase in total bilirubin occurs in cholestatic hepatitis, metastatic liver cancer, primary biliary cirrhosis, Gilbert's syndrome, B ₁₂ -deficiency anemia, helminthic invasions, fly agaric poisoning. During pregnancy, an increase in bilirubin may indicate a curved bile duct.

A significant increase in the concentration of bilirubin in the blood is manifested by jaundice, which looks like a yellow staining of the skin, visible mucous membranes and sclera.

A decrease in bilirubin occurs with a low-calorie diet, fasting.

Alanine aminotransferase

Alanine aminotransferase (ALT, ALT) is an endogenous enzyme of the aminotransferase subgroup, a participant in amino acid metabolism. It is found in large quantities in the liver and kidneys, in smaller quantities in the heart muscle, skeletal muscles, spleen, lungs, pancreas. When the cells of these organs are destroyed as a result of any pathological processes, alanine aminotransferase is released into the blood.

Determination of the level of alanine aminotransferase is important for the detection of liver diseases, myocardial pathologies, it is used in the examination of contact persons from the focus of viral hepatitis and donors, as well as for monitoring hepatitis therapy.

ALT rises in pancreatitis, shock, skeletal muscle injuries, burns, extensive myocardial infarction, heart failure, viral hepatitis, toxic liver damage, cirrhosis, liver cancer, alcoholism, the use of a number of drugs (psychotropic drugs, contraceptives, antibacterial drugs, immunosuppressants, drugs for chemotherapy, etc.).

In the case of severe liver damage, the number of cells producing ALT decreases, its concentration in the blood may decrease - this is observed in cirrhosis, liver necrosis. Also, the level of the enzyme decreases with hypovitaminosis B ₆.

Aspartate aminotransferase

Aspartate aminotransferase (AST, AsAT) is an endogenous enzyme, another participant in amino acid metabolism, found in the liver, kidneys, heart, skeletal muscles, spleen, pancreas, lungs and nervous tissue. With the development of myocardial infarction, the activity of this enzyme can increase 20 times, which is detected even before the appearance of ECG signs and is used in the early diagnosis of a heart attack.

The AST study is important for the diagnosis of pathologies of the liver, heart and skeletal muscles.

An increase in the indicator occurs with pulmonary artery thrombosis, acute rheumatic heart disease, myocardial infarction, heart surgery, angina pectoris, hepatitis, cholestasis, liver cancer, pancreatitis, skeletal muscle injuries.

A decrease in AST is observed in severe liver damage, lack of vitamin B ₆. In case of liver rupture, the value of aspartate aminotransferase, as a rule, determines the prognosis - an unfavorable prognostic sign is a sharp decrease in the level of AST and ALT in the presence of hyperbilirubinemia.

Urea

Urea is the main final protein breakdown product produced by the liver and excreted primarily by the kidneys. The concentration of urea in the blood changes not only during pathological processes in the body, but also depends on some physiological factors (nutrition, physical activity, age) and medication intake.

In children of the first days of life, the level of urea in the blood corresponds to that in adults, in older children, the normal values are slightly lower, which is taken into account when decoding the biochemical blood test.

An increase in the concentration of urea in the blood occurs with dehydration of the body, inappropriate nutrition (excess protein intake), increased protein breakdown, glomerulonephritis, pyelonephritis, kidney tuberculosis, heart failure, shock conditions, severe bleeding, burns, intestinal obstruction, prostatic adenoma, stones, fever. A short-term increase in urea levels is observed with intense physical exertion.

A decrease in this indicator is observed during pregnancy, after hemodialysis, with severe liver damage (acute hepatodystrophy, hepatitis, cirrhosis), increased protein utilization, deficiency or absence of enzymes involved in the urea formation cycle, insufficient protein intake (with vegetarianism, starvation), poisoning with arsenic, phosphorus.

Creatinine

Creatinine is another end product of protein metabolism, which is produced in the liver and takes part in the production of energy during muscle contractions, and is excreted in the urine. In the body of a healthy person, this process occurs constantly, therefore the level of this indicator is usually determined by the volume of muscle mass. Consequently, in men, the concentration of creatinine is higher than in women, and in children it changes as they grow older. Determination of the level of creatinine in the blood is necessary to assess the function of the kidneys, to determine the pathologies of skeletal muscles.

Blood for biochemical analysis is taken from a vein, in the morning and on an empty stomach

An increase in creatinine levels occurs with an unbalanced diet (predominance of meat foods in the diet), dehydration of the body, excess muscle mass, severe internal bleeding, acute and chronic renal failure, taking certain medications (cephalosporins, androgens, salicylates, aminoglycosides, barbiturates), trauma, surgical interventions, prolonged squeezing syndrome, exposure of the body to ionizing radiation.

A decrease in creatinine may indicate muscle atrophy, a vegetarian diet, overhydration, and corticosteroid use. It is also lowered during pregnancy and in people of advanced age.

Alpha amylase

Alpha-amylase (amylase, diastase) is a digestive enzyme that breaks down food carbohydrates, synthesized in the pancreas and salivary glands, and excreted by the kidneys. In children of the first year of life, normal alpha-amylase values are low, since they do not include complex carbohydrates in their diet.

Determination of the concentration of this enzyme is used in the diagnosis of pancreatitis (acute or exacerbation of chronic), cystic fibrosis, identifying the causes of acute abdominal pain.

An increase in the level of alpha-amylase is observed in pancreatitis, pancreatic cyst, acute peritonitis, renal failure, diabetes mellitus, cholelithiasis. Decrease - with hepatitis, pancreatic insufficiency, toxicosis of pregnancy, cystic fibrosis, pancreatectomy.

Calcium

Calcium is a blood electrolyte that contributes to the maintenance of hemostasis, normal heart rate, is involved in nerve conduction, bone formation, tooth mineralization and many other processes in the body.

A significant increase in its concentration is observed in malignant neoplasms with bone damage, dehydration, acute renal failure, thyrotoxicosis.

A decrease in calcium content is observed with rickets, chronic renal and hepatic failure, pancreatitis.

Iron

Iron in the body is an electrolyte, whose main task is to bind, transport and transfer oxygen to tissues, i.e., their nutrition.

An increased concentration of iron in the blood is characteristic of liver diseases, acute leukemia, and lead poisoning. It is also observed with certain medications and excess food intake.

A decrease in iron is observed in iron deficiency anemia, infectious diseases, hypothyroidism, liver and kidney diseases, and significant blood loss.

Magnesium

Magnesium is essential for normal metabolism, the functioning of the heart, nervous and muscle tissue.

An increase in its concentration occurs with dehydration, renal failure, hypothyroidism.

If there is a decrease in the level of magnesium, then there is a violation of the intake or assimilation of the trace element. It occurs in pancreatitis, hyperthyroidism, alcoholism, renal failure.

The listed indicators are the main ones. If necessary, some others can be determined during biochemical analysis.

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