Advice 1: How much blood can lose without danger to life

Bleeding resulting from trauma or disease, can pose a real threat not only health, but also of human life in the case that the blood loss was quite large.
How much blood can lose without danger to life

The danger of blood loss


Blood is the most important substance in the human body, one of the main functions of which is to transport oxygen and other essential substances to the heart to the tissues. Therefore, the loss of a significant amount of blood can significantly affect normal functioning of the body or even lead to death.

In total the body the average adult contains about 5 liters of blood. While some of its parts it can lose without any harm to themselves: for example, the volume of blood taking over once the donor is 450 milliliters. This number is considered quite safe for an adult. More or less serious problem could be the loss of 20% of total blood volume or more.

The scope and nature of blood loss


Doctors say that the severity of blood loss to human life in a particular case depends not only on its volume but also the nature of the bleeding. So, the most dangerous is bleeding fast, in which people within a short period of time not exceeding a few tens of minutes, loses a significant amount of blood.

With the loss of about one liter of blood, or about 20% of total blood volume circulating in the body, the heart ceases to obtain a sufficient volume of blood for circulation, you suffer the disruption of heart rhythm, decrease blood pressure level and pulse rate. However, if the bleeding fails to stop at this stage, she usually does not bear a significant threat to human life, and with adequate nutrition and rest, the body is capable to restore lost volume.

In case of loss from 20% to 30% of the blood within a relatively short time, equivalent to the volume of 1-1,5 liters of blood for an adult, there is increased sweating and thirst, nausea, possible vomiting. The person can't breathe, he becomes apathetic, his hands shaking and vision getting fuzzy. In this case, even if you stop the bleeding self-service recovery of lost volume, as a rule, is difficult and a person needs a blood transfusion.

The rapid loss of 2-3 liters of blood, that is 30% or more of the total amount present in the body, the skin surface of the person becomes cold, he visibly pales, and his face and limbs bluish tint. In most cases, this blood loss is accompanied by loss of consciousness, often falling into a coma. In this case, to save a man's life can only immediate blood transfusion. Rapid loss of more than 50% of the total amount of blood present in the body, is considered fatal.

If the blood loss is gradual, for example when internal bleeding, the body has time to adapt to the situation and able to withstand a significantly large amount of blood loss. For example, in medicine known cases of survival with the loss of 60% of blood after timely intervention.

Advice 2: How many liters of blood?

The blood circulating in the human body through the blood vessels, is a liquid substance consisting of red blood cells – red blood cells, leukocytes - white blood cells, platelets and plasma. Blood plays a vital function in the body, providing, in particular, the relationship between its organs, in addition, its changing composition – an indicator of health status. But the amount of blood formed in the adult human body remains almost unchanged.
How many liters of blood?

Functions of the circulatory system


In addition to transport various nutrients and oxygen from some bodies to others through blood circulation in the body is the transfer of metabolic waste products and carbon dioxide to the organs through which the output of waste products: kidneys, intestines, lungs and skin. Blood also performs a protective function, white blood cells and proteins contained in plasma, involved in neutralization of toxins and the absorption of the germs that enter the body. By the blood the endocrine system provides regulation of all vital functions and processes, as the hormones produced by the endocrine glands, also are transported by the bloodstream.

Lymph, interstitial fluid and blood make up the internal environment of the organism, constancy of its composition and physico-chemical characteristics of supported mechanisms of regulation and are an indicator of health. In the case of pathological or inflammatory processes associated with a particular disease, the change and composition of blood, so her analysis – the first thing you need doctor for diagnosis.
Dangerous to humans is the rapid decline in the number of blood, for example, in the case of open wounds, which cause a sudden drop in blood pressure.


Because in its composition the blood is a liquid in which are suspended the formed elements, its composition is determined by centrifugation. In human blood plasma is about 55-58%, and the remaining formed elements - from 42 to 45%, and in the blood of men a little more than in the blood of women.

How much blood contains in the human body


Currently, the amount of blood circulating in the human body, is determined with a fairly high degree of accuracy. This method is used when the blood is introduced metered quantity of a substance that is not immediately derived from its composition. After using it for some time evenly distributed throughout the circulatory system, take a sample and determine its concentration in the blood. Most often as such a substance is harmless to the body colloidal dye, e.g., Congo mouth. Another way to determine the amount of blood in the human body is the introduction into the blood of artificial radioactive isotopes. After some manipulation of the blood, it is possible to count the number of red blood cells, which penetrated the isotopes, and then the value of radioactivity of blood and blood volume.
If the blood turns the excess fluid is distributed into the skin and muscle, and also excreted through the kidneys.


As was found, the average amount of blood is about 7% by weight, if your weight is 60 kg, the blood volume will be equal to 4.2 liter, 5-liter volume circulates in the body, weighing in at 71.5 kg. its Volume can vary from 5 to 9%, but usually these fluctuations are intermittent and associated with fluid loss or, on the contrary, the introduction of it in the blood, and profuse bleeding. But the regulatory mechanisms acting in the body, maintain the amount of the total blood it permanent.
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