Biochemistry of blood is one of the most common and informative tests that doctors prescribe when diagnosing most diseases. Seeing its results, you can judge the state of work of all body systems. Virtually every disease is reflected in the biochemical blood test.
What you need to know
Blood is drawn from the vein on the elbow, less often from the veins on the wrist and the
About 5-10 ml of blood is drawn into the syringe.
Later blood for biochemistry in a special tube is placed in a specialized device that has the ability to determine the required parameters with high accuracy. It should be borne in mind that different instruments may have slightly different limits of the norm for certain indicators. The results will be ready with the express method during the day.
How to prepare
Biochemical examination is performed in the morning on an empty stomach.
Before giving blood, you must refrain from drinking alcohol during the day.
The last meal should be the previous night, not later than 18.00.Do not smoke two hours before the change. Also, exclude intense physical activity and, if possible, stress. Preparation for analysis is a responsible process.
What is included in the biochemistry of
There are basic and extended biochemistry. It is inappropriate to determine all the indicators that are only possible. It goes without saying that the price and quantity of blood needed for analysis increases. There is a conditional list of basic indicators that are assigned almost always, and there are many additional ones. They are appointed by the doctor depending on the clinical symptomatology and the purpose of the study.
The assay is done using a biochemical analyzer in which blood test tubes are placed.
- Total protein.
- Bilirubin( direct and indirect).
- ALT and AST.
- Alkaline phosphotase.
- C-reactive protein.
- Rheumatoid factor.
- Creatinine phosphokinase.
The list is incomplete, there are still many narrowly directed indicators for the diagnosis of metabolism and violations of internal organs. Now consider some of the most common blood biochemical indicators in more detail.
Total protein( 65-85 grams / liter)
Displays the total amount of protein in the blood plasma( both albumin and globulin).
May be elevated by dehydration, due to loss of water with repeated vomiting, with intense sweating, intestinal obstruction and peritonitis. Also increases with myeloma, polyarthritis.
This indicator decreases with prolonged starvation and malnutrition, diseases of the stomach and intestines, when the intake of protein is disturbed. With liver diseases, its synthesis is disrupted. The synthesis of protein in some hereditary diseases has also been disrupted.
Albumin( 40-50 grams / liter)
One of the plasma protein fractions. With a decrease in albumin develop edema, down to the anasarca. This is due to the fact that albumin binds water. At its considerable decrease, the water does not keep in the bloodstream and leaves in the tissue.
Albumin is reduced under the same conditions as the total protein.
Total bilirubin( 5-21 mkmol / liter)
Total bilirubin includes direct and indirect bilirubin.
All reasons for increasing total bilirubin can be divided into several groups.
Extrahepatic - a variety of anemia, extensive hemorrhage, that is, the state, accompanied by the destruction of red blood cells.
Hepatic causes are associated with the destruction of hepatocytes( liver cells) in cancer, hepatitis, liver cirrhosis.
Disturbance of bile outflow due to obstruction of the bile duct with stones or a tumor.
With increased bilirubin, jaundice develops, the skin and mucous membranes acquire icteric hue
The norm of direct bilirubin is up to 7.9 μmol / liter. Indirect bilirubin is determined by the difference between general and direct. Most often, its increase is due to the breakdown of red blood cells.
Creatinine( 80-115 μmol / liter)
One of the main indicators that characterizes the function of the kidneys.
This indicator increases with acute and chronic kidney disease. Also with increased destruction of muscle tissue, for example, in rhabdomyolysis after over-intensive physical exertion. It can be increased with the disease of the endocrine glands( hyperthyroidism, acromegaly).If a person consumes a large number of meat products, elevated creatinine is also guaranteed.
Creatinine below the norm is not of special diagnostic value. May be reduced in vegetarians, in pregnant women in the first half of pregnancy.
Urea( 2.1-8.2 mmol / liter)
Shows the state of protein metabolism. Characterizes the work of the kidneys and liver. The increase in urea in the blood can be if the kidney function is disturbed, when they can not cope with its excretion from the body. Also with increased protein breakdown or increased intake of protein into the body with food.
Reduction of urea in the blood is observed in the third trimester of pregnancy, with a low protein diet and severe liver diseases.
Taking blood from a vein is a practically painless procedure.
Transaminases( ALT, AST, GGT)
Aspartate aminotransferase( AST) is an enzyme synthesized in the liver. In blood plasma, its content should not normally exceed 37U / liter in men and 31E / liter in women.
Alanine aminotransferase( ALT) - as well as the AST enzyme, is synthesized in the liver.
The norm in the blood of men is up to 45 units / liter, for women - up to 34 U / liter.
In addition to the liver, a large number of transaminases are found in the cells of the heart, spleen, kidneys, pancreas, in the muscles. An increase in its level is associated with the destruction of cells and the release of this enzyme into the blood. Thus, the increase in ALT and AST is possible with the pathology of all the above mentioned organs, accompanied by cell death( hepatitis, myocardial infarction, pancreatitis, necrosis of the kidney and spleen).
Gamma-Glutamyltransferase( GGT) is involved in the exchange of amino acids in the liver. Its content in the blood rises with toxic damage to the liver, including alcohol. Also increased the level of pathology of the bile duct and liver. Always increases with chronic alcoholism.
The norm of this indicator is up to 32 U / liter for men, up to 49 U / liter for women.
Low GGT is usually determined with cirrhosis of the liver.
Lactate dehydrogenase( LDH)( 120-240 units / liter)
Causes of increased urea in the blood
This enzyme is found in all tissues of the body and participates in the energy processes of oxidation of glucose and lactic acid.
Increased in liver diseases( hepatitis, cirrhosis), heart( heart attack), lungs( infarct-pneumonia), kidneys( various nephritis), pancreas( pancreatitis).
The decrease in LDH activity below the norm is insignificantly insignificant.
Alpha-amylase( α-amylase) is involved in the metabolism of carbohydrates, splitting complex sugars to simple sugars.
Increase the activity of the enzyme acute hepatitis, pancreatitis, parotitis. Some drugs( glucocorticoid, tetracycline) may also be affected.
The activity of amylase is reduced for pancreatic dysfunction and toxicosis of pregnant women.
Pancreatic amylase( p-amylase) is synthesized in the pancreas and enters the intestinal lumen, where excesses are almost completely dissolved by trypsin. Normally, only a small amount enters the blood, where the norm is normal in adults - no more than 50 units / liter.
Total cholesterol( 3.6-5.2 mmol / l)
On the one hand, an important component of all cells and an integral part of many enzymes. And on the other hand, it plays an important role in the development of systemic atherosclerosis.
Total cholesterol includes high, low and very low density lipoproteins. Increased cholesterol in atherosclerosis, impaired liver function, thyroid gland, with obesity.
Atherosclerotic plaque in a vessel - a consequence of elevated cholesterol
Cholesterol is lowered in a diet that excludes fat, with hyperthyroidism, with infectious diseases and sepsis.
Glucose( 4.1-5.9 mmol / liter)
An important indicator of the state of carbohydrate metabolism and the state of the pancreas.
Increased glucose can be after eating, so the analysis is taken strictly on an empty stomach. Also increases with the intake of certain drugs( glucocorticosteroids, thyroid hormones), with pancreatic pathology. Constantly elevated blood sugar is the main diagnostic criterion for diabetes mellitus.
Reduced sugar can be with acute infection, fasting, overdose of sugar-reducing drugs.
Electrolytes( K, Na, Cl, Mg)
Electrolytes play an important role in the transport of substances and energy to and from the cell. This is especially important for the proper functioning of the heart muscle.
A change in both the concentration and decrease direction leads to cardiac arrhythmias, up to cardiac arrest
- Potassium( K +) - 3.5-5.1 mmol / liter.
- Sodium( Na +) - 139-155 mmol / liter.
- Calcium( Ca ++) - 1.17-1.29 mmol / liter.
- Chlorine( Cl-) - 98-107 mmol / liter.
- Magnesium( Mg ++) - 0.66-1.07 mmol / liter.
Changing the electrolyte balance is associated with alimentary causes( impaired intake), impaired renal function, hormonal diseases. Also expressed electrolyte disturbances can be with diarrhea, indomitable vomiting, hyperthermia.
Three days before you donate blood for biochemistry with the definition of magnesium, you must not take its drugs.
In addition, there are a large number of indicators of biochemistry, which are assigned individually for specific diseases. Before donating blood, your doctor will determine which of the indicators are taken in your situation. The procedural nurse will perform blood sampling, and the lab technician will provide an analysis of the analysis. Indicators of the norm are given for an adult. Children and the elderly may differ slightly.
As you can see, a biochemical blood test is a very big help in diagnosis, but only a doctor can compare the results with the clinical picture.