What is the permissible norm of sugar in the blood of a person?

Glucose is the main energy material for the nutrition of body cells. From it through complex biochemical reactions are obtained so necessary for life calories. Glucose is available in stock in the form of glycogen in the liver, it is released when there is insufficient intake of carbohydrates with food.

The term "blood sugar" is not medical, rather it is used in colloquial speech as an outdated concept. After all, there are a lot of sugars( for example, fructose, sucrose, maltose), and the body uses only glucose.

The physiological norm of blood sugar varies depending on the time of day, age, food intake, exercise, and stress.

The blood sugar level is constantly adjusted automatically: it increases or decreases depending on the needs."Manages" this complex system of pancreatic insulin, to a lesser extent, the hormone of the adrenal glands - adrenaline.

Diseases of these organs lead to failure of the regulatory mechanism. Subsequently, there are various diseases that can first be attributed to a group of metabolic disorders, but eventually they lead to an irreversible pathology of the organs and systems of the body.

An investigation of the human glucose content is necessary to assess the health, adaptive response.

How the blood sugar is determined in the laboratory

Blood sugar analysis is performed in any medical institution. Three methods for determining glucose are used:

  • glucose oxidase,
  • orthotoluidine,
  • ferricyanide( Hagedorna-Jensen).

All methods are unified in the 70s of the last century. They are sufficiently verified for reliability, informativeness, simple in execution. They are based on chemical reactions with blood glucose. As a result, a color solution is formed which, on a special device, evaluates the color intensity and translates it into a quantitative indicator.

The results are given in international units for the measurement of dissolved substances - mmoles per liter of blood or in mg per 100 ml. For the transfer of mg / l in mmol / l, the figure must be multiplied by 0.0555.The blood sugar in the Hagedorn-Jensen study is slightly higher than in others.

Rules for taking glucose test: blood is taken from the finger( capillary) or from the vein in the morning up to 11 hours on an empty stomach. The patient is warned in advance that he should not eat between eight and fourteen hours before taking blood. You can drink water. The day before the analysis, you can not overeat, drink alcohol. Violation of these conditions affects the indicators of the analysis and may lead to incorrect conclusions.

If the analysis is carried out from venous blood, the permissible rates are increased by 12%.The norms of glucose in capillaries are from 3.3 to 5.5 mmol / l, and in veins - from 3.5 to 6.1.

In addition, there is a difference in performance when taking whole blood from the finger and vein with the level of glucose in the blood plasma.

Blood sampling
Taking capillary blood for sugar

The World Health Organization has proposed that in order to prevent diabetes screening, the upper limits of the norm should be taken into account:

  • from the finger and vein - 5.6 mmol / l;
  • in plasma - 6.1 mmol / l.

To determine which glucose rate corresponds to an elderly patient over the age of 60, it is recommended that the correction of the indicator be made annually at 0.056.

Patients with diabetes mellitus are recommended to use portable glucometers for self-determination of blood sugar.


The fasting blood sugar level has a lower and upper limit, it is different in children and adults, there is no gender difference. The table shows the standards depending on the age.

Age( years) Glucose in mmol / L
in children under 14 2.8 - 5.6
in women and men 14 - 59 4.1 - 5.9
in the elderly over 60 4, 6 - 6.4

The age of the child is of importance: for babies up to a month, 2.8-4.4 mmol / l is considered normal, from a month to 14 years, from 3.3 to 5.6.

For pregnant women, 3.3 to 6.6 mmol / l are considered normal. The increase in glucose concentration in pregnant women can indicate latent( latent) diabetes, so it requires follow-up.

The ability of the body to absorb glucose is important. For this, it is necessary to know how the index of sugar changes after eating, during the day.

Time of day Blood sugar level mmol / l
from two to four o'clock at night above 3.9
before breakfast 3.9 - 5.8
in the afternoon before lunch 3.9 - 6.1
before dinner 3.9 - 6.1
due to food intake after one hour less than 8,9
two hours less than 6,7

Evaluation of the results of the

research When receiving the results of the analysis, the physician should assess the glucose level as: normal, elevated or lowered.

Increased sugar content is called "hyperglycemia."

This condition is caused by various diseases of children and adults:

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  • diabetes mellitus;
  • of the endocrine system( thyrotoxicosis, adrenal disease, acromegaly, gigantism);
  • acute and chronic inflammation of the pancreas( pancreatitis);
  • pancreatic tumors;
  • chronic liver disease;
  • kidney disease associated with a violation of filtration;
  • cystic fibrosis - connective tissue damage;
  • stroke;
  • myocardial infarction;
  • auto-allergic processes associated with antibodies to insulin.

Hyperglycemia is possible after the transferred stress, physical activity, violent emotions, with an excess of carbohydrates in nutrition, smoking, treatment with steroid hormones, estrogens, caffeine preparations.

Hypoglycemia or reduced glucose level is possible with:

  • pancreatic diseases( tumors, inflammation);
  • cancer of the liver, stomach, adrenal glands;
  • endocrine changes( decreased thyroid function);
  • hepatitis and cirrhosis;
  • poisoning with arsenic compounds and alcohol;
  • overdose of medicines( insulin, salicylates, amphetamine, anabolic);
  • in premature infants and newborns from mothers with diabetes mellitus;
  • high temperature during infectious diseases;
  • prolonged starvation;
  • intestinal diseases associated with impaired absorption of nutrients;
  • excessive physical exertion.
Compact analyzer for small laboratories

Diagnostic blood glucose criteria for the detection of diabetes

Diabetes mellitus is a disease that can be detected even in a hidden form by the analysis of blood for glucose.

Simplified recommendations suggest that the level of glucose from 5.6 to 6.0 mmol / l "prediabetes", and 6.1 and more - diabetes.

The undoubted diagnosis is the combination of symptoms of diabetes and high blood glucose figures:

  • , regardless of food intake - 11 mol / l and higher;
  • in the morning 7.0 and above.

In case of doubtful tests, the absence of obvious signs, but the presence of risk factors, a stress test with glucose is carried out, or it is called a test for glucose tolerance( TSH), and in the old "sugar curve".

The essence of the technique:

  • , the analysis of fasting sugar is taken as the baseline level;
  • stir in a glass of water 75 g of pure glucose and give a drink inside( for children, 1.75 g for each kg of weight is recommended);
  • do repeat tests in half an hour, an hour, two hours.

Between the first and the last study you can not eat, smoke, drink water, exercise.

Decoding of the test: the glucose value before taking the syrup should be necessarily normal or below normal. With impaired tolerance, intermediate analyzes show( 11.1 mmol / L in plasma and 10.0 in venous blood).After two hours the level remains above normal. It says that while absorbing glucose is not digested, it remains in the blood and plasma.

As the glucose level rises, the kidneys begin to flow into the urine. This symptom is called glucosuria and serves as an additional criterion for diabetes mellitus.

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A blood test for sugar is a very important test in a timely diagnosis. Specific indicators are needed by the endocrinologist to calculate how many units of insulin can compensate for the insufficient function of the pancreas. Simplicity and universality of methods makes it possible to conduct mass surveys of large teams.