A biochemical blood test is done on an empty stomach or not. The food is understandable. Can I drink before the analysis? Why donor blood tests are taken on an empty stomach

The most common and affordable diagnostic procedure for many diseases today it serves. The study of the content of blood elements helps the attending physician to most fully determine the picture of the patient's health. A competent doctor will certainly tell the patient why blood is donated in the morning and on an empty stomach.

Types of blood sampling

For more complex types of examination, hormonal and. Blood sampling is carried out, depending on the purpose of the analysis, from ring fingers arms or ulnar vein.

In order for the research results to be as objective as possible, the patient must observe a number of simple rules when contacting a clinical laboratory. Anyone who is used to carefully monitoring their health knows that a blood test is taken strictly on an empty stomach.

In order to determine in a timely manner what is the cause of an unclear malaise, it is first of all necessary.

In any case, if or veins, it is taken in the morning and on an empty stomach.

The main clinical indicator in this case will be the number of red blood cells - erythrocytes. These blood cells are responsible for oxygenation of tissues. A decrease in the level of hemoglobin in the blood - (this is the name of the protein contained in red blood cells and is responsible for supplying cells with oxygen), ultimately leads to anemia. - not good either. Increased concentration oxygen in the cells entails the adhesion of red blood cells. This leads to capillary blockage and the development of thrombocytosis.

The blood may indicate dehydration. This is another good reason why a complete blood count is needed.

Platelets are blood elements responsible for. To stop bleeding from damaged vessels, clots form at the site of injury - blood clots. observed with a compensatory purpose after undergoing operations, and in addition with blood pathology. occurs with insufficient liver function, diseases affecting Bone marrow etc.

White blood cells, or leukocytes, are usually larger in size, but they are found in much lower numbers. Their main function is to protect the body from various infections.

An increase in the number of leukocytes per unit of blood volume indicates the presence of inflammation in any organ.

When venous blood is donated

Venous blood is donated in a number of cases. First, when it is impossible to collect a sufficient volume of blood for a number of complex studies. Therefore, in laboratories, blood is taken for analysis from a vein.

The last meal can be no later than 8-12 hours before blood sampling. It is only allowed to drink a little water, but not tea or coffee. In some cases, before surrender general analysis blood, a light breakfast is allowed, consisting of unsweetened porridge with tea without sugar, it is forbidden to eat dairy products, butter, fruits. In this case, it is permissible to have breakfast no later than one hour before blood sampling. By this time, the stomach will already be empty and, in fact, the examination will be performed correctly. In the evening before donating blood from a vein, it is recommended to stop eating fatty foods, alcohol, and smoking.

Biochemical analysis - strictly on an empty stomach

Before putting on biochemical analysis blood is recommended not to eat for 8-12 hours. Why is this so important?

A biochemical blood test is performed according to 11 criteria and allows the doctor to determine how the liver, kidneys, cardio - vascular system... Therefore, it is fundamentally important to pass biological fluid without excess sugar and excess fat in it. Biochemical analysis reveals the presence of diabetes mellitus, atherosclerosis, chronic inflammatory processes, heart attacks, strokes.

A biochemical blood test is taken strictly on an empty stomach, since an incorrect blood sampling technology can misinform a specialist and lead to a diagnostic error.

In order to identify the existing violations in the work of female endocrine system it is necessary to examine the blood for the content of female sex hormones. Every woman in reproductive age, must undergo a periodic examination to prevent and timely detect failures in the work of the endocrine system.

For the examination, it becomes necessary to control hormones, and it is important to do this in the morning on an empty stomach. In addition, it is necessary to take into account the day of the woman's menstrual cycle. The level of follicle-stimulating and luteinizing hormones is determined on the 4-5th day of the cycle, the level of ovarian hormones - on the 21-23rd day.

Tests for infections

A blood test is one of the leading methods for diagnosing bacterial and viral infections. Like all other tests, blood is donated on an empty stomach. For maximum accurate diagnosis tests for the presence of infections are carried out repeatedly in different time, in order to determine the phase of infection and assess the status immune defense organism. It is important to conduct the study several times under similar conditions: at about the same time of day and always in the same laboratory. With the help of such tests, hepatitis and syphilis can be detected.

Maximum early diagnosis such serious infectious diseases will allow you to pick up best treatment and reduce harm to health.

Patient rules

Regardless of the method of donating blood, the patient must follow simple rules before donating blood:

Donate blood in the morning on an empty stomach and on an empty stomach, give up cigarettes for an hour before taking blood.
You should not eat for 5-6 hours. Optimal time- 10 a.m.

Some species genetic research allow you to take tests even after eating. In addition to all of the above, the result is influenced by the emotional background and physical exercise... Arriving at the clinical laboratory, you need to sit down for a while to rest and normalize breathing, calm down and then go to take the test.

The child is repeatedly faced with the need to perform a blood test. The results of the analysis of blood components will tell about pathological processes v child's body, or, conversely, about their absence. They will allow you to quickly diagnose and prescribe therapy. Donating blood requires some preparation that adults should be aware of.

Every child faces the blood donation procedure

Why do you need a complete blood count?

The general analysis itself is quite simple, but informative. Blood from a finger from both a small and an adult patient is taken to determine many of its indicators:

Basic rules for preparing for analysis

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In order not to distort the result of the study, many experts prohibit eating before donating blood from a finger, but there are other factors that can affect the result. For example, it is affected by certain medications that a small patient may take. In order for the analysis to be informative, they prepare for it in advance:
A visit to the laboratory is planned in the early morning, preferably from 7-00 to 10-00. Many laboratories work until 12-14 hours, but this time will be difficult for a child who has not had breakfast. In addition, blood counts change in the afternoon.
Before taking blood, they do not plan to visit the X-ray room and physiotherapy. This affects the result.
The interval between the last meal on the eve of the test and the blood sampling procedure is 12 hours. An abundance of sweets, muffins, fried foods in the diet is prohibited. Otherwise, the laboratory picture will change, especially with regard to the number of leukocytes.
It is allowed to drink clean water in moderate portions without additives, dyes, preservatives and sugars. Teas, compotes, fruit drinks, decoctions, milk are also prohibited.

Before taking a general blood test, it is allowed to drink a small amount of clean water
With ARVI, an analysis is prescribed to determine the complexity of the course of the disease - it is taken as directed by a doctor. When to come scheduled visit to the laboratory, to acute period respiratory diseases it is canceled and postponed for 1.5-2 weeks from the moment of recovery.
It is better to exclude any anxiety before the procedure, to cancel training with increased load.
After operations, major interventions, the study is planned a week later.

All deviations from the rules should be warned by the laboratory assistant or doctor. If the patient is taking medications that may affect the interpretation of the analysis, the doctor will advise on what can be done in this case. Sometimes a break in therapy is allowed.
Features of blood sampling for a general analysis in an infant
As in other cases, to complete clinical analysis, they will take from the baby capillary blood from the finger.

The rule “do not eat before donating blood” does not apply to babies in the first year of life!
Children under 1 year old do not have to (and more often than not, it is impossible) to withstand a break without food:
Newborns in the first week of life will have to take a blood test more than once. Abstaining from feeding the baby is out of the question.
It is impossible to explain to babies under one year old why they were not fed before painful procedure... Breakfast is a must for them - milk, porridge, vegetables, lean meat, depending on what the baby is accustomed to eating. Then there is a break of 3 hours, and you can go to the laboratory. The algorithm is as follows: wake him up early, feed him, go for a walk and wait the right time go to donate blood.
Psychological preparation is important before passing. In the evening, the baby is offered a calm game or is shown a cartoon with a doctor character. In the morning they tell him where and why they are going. Be sure to buy a children's scarifier for blood sampling.

Should a child over a year old donate blood on an empty stomach or can he be fed?
A general blood test for children over a year old is taken on an empty stomach - this is an unbreakable rule. It applies to both children and adults. The attending physician needs real indicators of how the patient's body is working.
If there is a suspicion of infectious process, inflammation, exacerbation chronic illness, then this is what the doctor will confirm or deny according to the analyzes. If the patient is recovering, this should be seen in the results of the study.
Eating food before the procedure can be reflected in the deciphering of the analysis and lead to its false interpretation, and then to the wrong diagnosis.
Example: the child was fed before the study, the components of the food, when absorbed into the blood, caused a change in its composition, affecting the viscosity, leukocyte formula, the ratio of proteins, fats and more. In the decoding, the doctor sees signs of an inflammatory process, which in fact are not. A therapy is prescribed that is unnecessary and dangerous for the patient. This outcome will not please any parent.
It is good if the doctor finds out the reasons for the false readings. If not, then additional examinations and procedures may be prescribed, which is tiresome for the baby and ineffective in general.
An exception is made only for small patients suffering from diabetes mellitus and pancreatitis (we recommend reading :). They are contraindicated big breaks between meals and fasting blood donation. Before blood tests, such children are advised to eat a small portion of cereal porridge in water, fresh vegetables or crackers, and cheese.
The conclusion is simple - all other categories of children (over 1 year old) take a general blood test strictly on an empty stomach, subject to simple rules. Children are prepared in advance for the procedure, explaining its importance. To make everything go smoothly, a visit to the laboratory is made early in the morning. Then the baby can and should be fed.

Blood tests are the most accurate methods laboratory diagnostics state of the body. With their help, the doctor assesses the state of the patient's body, the work of his organs and systems, the possibility of developing inflammatory, allergic processes. Of course, it is very important to properly prepare for donating blood for research. Often, having received a referral for research, the patient hears from the doctor the requirement to take a fasting blood test. Consider which blood tests need to be taken on an empty stomach, and which studies do not require such a condition.

What blood tests are taken on an empty stomach

First, let's define what the word "fasting" is. On an empty stomach means that from time to time last admission food should pass at least 12 hours.

General blood analysis

But many doctors are of the opinion that it is not necessary to have a complete blood count on an empty stomach, and they recommend that at least three hours have passed since the last meal. At the same time, it is desirable that before donating blood, there are no fatty, spicy, salty, sweet foods in the patient's diet.

Blood chemistry

Be sure to donate blood on an empty stomach for biochemical analysis (blood biochemistry). This is due to the fact that nutrients that enter the body can significantly change the indicators of the biochemical blood test.

So, after 12-14 hours of fasting, blood is taken for lipoproteins, cholesterol. To determine the concentration of urea, in addition to abstaining from food for 12 hours, it is recommended to adhere to a special diet for three days before donating blood. It excludes meat, fish, liver, kidneys, tea, coffee.

Another indicator of blood biochemistry that will change after a meal is glucose. Even drinking tea with sugar in the morning will distort the result of this analysis.

Bilirubin

Bilirubin is a bile pigment that is found in the blood and excreted in the bile. It is determined to diagnose diseases of the liver, gallbladder.

Lipid profile

Strictly on an empty stomach, it is necessary to donate blood for analysis to determine the parameters lipid profile- triglycerides, cholesterol, HDL (lipoproteins high density), LDL (low density lipoprotein).

Blood sugar

A blood sugar test also refers to studies for which blood is taken on an empty stomach. Any food taken before analysis will significantly change the research result.

Many doctors insist on the need to donate blood on an empty stomach for testing for HIV infection, hepatitis, and syphilis.

What blood tests can you take on an empty stomach?

There are blood tests that do not require long-term abstinence from food. The most common such studies include the following:

analysis for blood group and Rh factor;
tests for hormones (except for tests for hormones TSH and parahormone);
blood clotting test;
tests for tumor markers;
tests for sexually transmitted infections.

In any case, when receiving an appointment for a blood test, the patient should check with the doctor at what time it is best to take it and whether it is necessary to take it on an empty stomach.

Everyone knows that it is undesirable to eat before laboratory tests, but few are interested in whether it is possible to drink water before donating blood. This point is omitted in the recommendations of the attending physician, but it is important. Failure to comply with the rules for taking liquids affects the objectivity of test results... In order to correctly assess the state of human health and identify an ailment on early stages, blood tests must be carried out in accordance with all the rules. We will find out if they include a ban on water or other liquid.

What blood tests can a doctor prescribe?

What does blood test mean? This type of research involves taking a small amount of blood to study its composition. The doctor may prescribe the following tests for diagnostic purposes:

General... It is prescribed for almost everyone who has complained to a doctor. It makes it possible to make a preliminary diagnosis and prescribe additional studies.
Biochemical analysis... Advanced methodology to identify operational problems internal organs, metabolic disorders, and clarify the preliminary diagnosis.
For sugar... Needed to identify a violation.
For hormones... The method is based on measuring the concentration and bioactive substances produced by the human glands. This allows you to identify the causes of various diseases, including endocrine ailments, infertility.
It is required to identify a latent oncological process before the first signs of the disease.
For HIV, hepatitis and other infections.

Research like this helps correct diagnosis, because the composition of a person's blood changes only under the influence of pathogenic factors: infection, inflammation, imbalance of hormones or glucose levels, dysfunction of internal organs.

How to prepare for a blood test?

When a doctor issues a referral for a particular study, he always warns about the rules for preparing for it or hands over a memo. Forgetful patients can find this information on the clinic's information boards.

Blood donation is usually done on an empty stomach in the morning. At this time, its composition is best suited for research. On the eve of the procedure, it is forbidden to eat any dishes so that their components do not affect chemical composition the main body fluid. If an urgent procedure is necessary, blood is taken immediately. If the patient is not unconscious, he is asked what he ate and drank in the near future.

It is important to remember that doctors do not inform about restrictions out of a desire to somehow infringe on the patient. Without this, it is difficult to obtain correct results for further diagnosis.

So, what rules must be followed by those who are assigned to donate blood:

Three days before the study do not eat fatty and spicy dishes, sauces, alcoholic beverages.
The last meal should be 12 hours before the procedure... Usually this is a light dinner that includes cereals, steamed vegetables, dairy products... At this time, physical activity, sports, emotional stress should be excluded.
Before the exploration you can not smoke and take medications.

Is it possible to drink liquid before an ultrasound abdominal cavity? Preparation rules and diet

If the patient needs a medication, the doctor is warned about this when an analysis is prescribed. Some studies require taking certain medications or formulations when donating blood in order to identify the effect of a pharmaceutical on the patient's body. For example, an exercise sugar curve assumes that the second phase is glucose added to tea or warm water.

For other studies, 12 hours before blood collection, neither tea, nor coffee, nor soft drinks, nor mineral water, nor sweet juices, jelly and compotes are allowed. This, perhaps, does not apply only to a general blood test. But even with him, you should not drink these drinks in the morning before the procedure.

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Should you drink water before donating blood?

The doctor practically never informs the patient about ordinary water, and there is no such information in the memos. And the patients themselves are rarely interested in this. But in vain. After all, even pure, non-mineralized water can change the results of some research. For what tests you can drink water before donating blood, and for what it is prohibited:

A glass of clean water will not harm general blood tests. Its components cannot influence the results. Sometimes the doctor even recommends taking a bottle of water with you and drinking a couple of sips before the procedure to relieve nervousness. This advice will come in handy for mothers of sick babies - it is difficult for young children to control their thirst. But this only applies to pure water, without dyes, carbonation, sweeteners and mineral inclusions. Such drinks can distort the level data and.
When determining the amount of sugar, it is undesirable to lean on water.... But it is allowed to drink a little before the procedure: dilute blood glucose pure water can not.
You cannot drink water from a vein before biochemical analysis. This is a subtle, thorough study that requires strict adherence to the rules of procedure. Even pure water can influence the results of research related to blood biochemistry. Especially if the task is to clarify the diagnosis of ailments of the excretory organs. Water, even clean water, can completely change performance. uric acid, and other results can be distorted.
In hormonal studies, pure water does not affect the indicators, therefore, drinking some water if the throat is dry is allowed. The same applies to donating blood for tumor markers, as well as identifying causative agents of infectious diseases - HIV,

We often have to deal with various laboratory tests. However, each of them has certain nuances, on which the correctness of the result depends.

General blood analysis

Every person has come across a general blood test at least once in his life. It is the main and common research in the diagnosis various diseases. This method shows the course of many processes in the body and reveals internal pathologies... We will also consider whether they take a general blood test on an empty stomach.

What you need to know about research

Only a qualified specialist can tell about the state of your body based on the results of this diagnosis. But you can get an idea of whether you are healthy or not, even before your doctor's appointment. To do this, it is enough to understand whether your indicators are normal or deviate from the standard. Let's consider the main ones:

Hemoglobin is the main component of red blood cells, or erythrocytes. Takes part in the transport of oxygen to organs and tissues. Promotes elimination carbon dioxide... With an insufficient level of hemoglobin, iron deficiency anemia develops. If this indicator is overestimated, we can talk about compensation for the lack of oxygen in the body.
Red blood cells are cells that are filled with hemoglobin. The main function is oxygen transport. The main indicator in the diagnosis of anemia.
Hematocrit - shows the percentage of red blood cells from the total blood volume. Displays the severity of the anemia.
Leukocytes are white cells. The main function is to recognize and neutralize viruses and bacteria. At inflammatory process in the body, the level of leukocytes rises. With an underestimated indicator, attention should be paid to the functioning of the endocrine system.
Lymphocytes - the main cellular elements immune system... Provide the production of antibodies.
Monocytes - cleanse the foci of inflammation and regenerate them.
Platelets - take part in clotting.
ESR - displays the rate at which erythrocytes are deposited. Is a non-specific indicator pathological changes in organism.
The color indicator is the amount of hemoglobin in erythrocytes. Not only the quantitative content of erythrocytes is taken into account, but also their volume.
Leukocyte formula - different kinds leukocytes, expressed as a percentage.

Each laboratory uses its own values and methods for diagnostics. Therefore, a repeated clinical analysis is desirable to be carried out in the same hospital and at approximately the same time. One of the problematic questions is this: is a general blood test taken on an empty stomach or not?

Factors affecting the state of the blood

The doctor who issued the referral for the analysis must inform about some points. Some of them are listed below.

Influence drugs for this analysis.
Availability bad habits(smoking, drinking alcoholic beverages).
Physical and emotional stress.
Passing medical procedures(for example, X-ray).
If a woman passes the diagnosis, then notify menstrual cycle, pregnancy, menopause, etc.
A general blood test is taken on an empty stomach or not.

Fence preparation rules

To exclude moments that might change clinical picture patient, several rules should be followed:

A general blood test must be taken on an empty stomach - from 7-00 to 12-00 in the morning. The break between meals should be at least twelve hours. During the last meal, you should limit coffee, strong tea, sweet and flour products, fried, salty and spicy foods.
Three days before the diagnosis, completely exclude alcohol intake.
If possible, stop taking medications.
You should refrain from smoking one hour before collection.
If the fence is planned, then it should be postponed if there is viral infection and take it no earlier than one and a half to two weeks after it.

If these rules are violated, you should inform the attending physician and the laboratory.

Drawing blood from a vein or from a finger

For a more extensive and reliable diagnosis it is recommended to take blood from a vein. The procedure itself takes only a few seconds and is practically painless for the patient. The attending physician should clarify the type of analysis and get advice on whether a biochemical and general blood test is performed on an empty stomach or not. All recommendations must be followed in strict order.

Blood test procedure

Most often, blood is taken from the finger. For more full research it is recommended to take a sample from a vein. V in this case a general blood test is required on an empty stomach, only the use of liquid is allowed, preferably only water.

Types of blood tests

There are two main types of blood tests:

General clinical analysis - the quantitative content of blood cells. You can take a general blood test on an empty stomach, although a light breakfast in the form of porridge without sugar and oil, unsweetened tea, and an apple is allowed.
Biochemical analysis - the definition of various substances in the blood is added to the previous indicators. Unlike the previous type of analysis, the question of whether a general blood test is taken on an empty stomach or not is not worth it. It is handed over only after a twelve-hour abstinence from food.

The body perceives juice, tea, coffee as a complete food. It is allowed to receive only clean non-carbonated water in small quantities.

In what cases can you take a complete blood count on an empty stomach?

The term "fasting" means that the fasting period must be at least twelve hours before the time of the test.

The most common diagnosis is a clinical blood test. Many patients wonder how a complete blood count is taken, on an empty stomach or not. Doctors differ. Some argue that pre-fasting is necessary. But most recommend refraining from eating only three to four hours before the test.

Types of blood tests that are taken only on an empty stomach:

Blood biochemistry.
Blood test for cholesterol.
Blood for lipoproteins.
Blood sampling for bilirubin.
Determination of the lipid profile.
Blood sugar levels.
Research of HIV infections.

These types of tests require adherence to all doctor's instructions.

Types of tests that do not depend on food intake

The most common tests, in which the patient may not be tormented by doubts whether a complete blood count is being taken on an empty stomach or not, are:

Determination of blood group and Rh factor.
Hormonal types of analyzes (with the exception of some indicators).
Blood for clotting.
Determination of tumor markers.

In any case, the doctor is obliged to explain the rules for donating blood to prevent distortion of laboratory results.

Child study

This analysis is one of the first to be taken from a child after birth. As a rule, the survey is carried out at the age of five days, one month, six months, one year, five and ten years. The main indicators are checked - the level of hemoglobin, the number and volume of erythrocytes, leukocytes. Be sure to have a sufficient level of platelets in the blood, hematocrit, ESR.

Indicators of blood test results in children are different age category are different from each other. The older the child, the more different his primary data are, and the more they are close to the norm of an adult. From the age of thirteen and older, the indicators of an adult are taken as the basis.

The rules and requirements for children when taking a general blood test are not much different from adults.

It is a little more difficult when it is necessary to submit a sample for biochemistry. In infancy, babies eat every two to three hours. The principle of a twelve-hour fast does not apply to them. Blood sampling for biochemical analysis is carried out two hours after the last meal.

If the child has already grown up and realizes the need for blood sampling, you need to try to create conditions in which he will not be exposed to stress. You should distract your baby as much as possible from what is happening in the queue (for example, baby crying). You can try to play with him his favorite game, tell a fairy tale, read a book.

With direct blood sampling for analysis, if the child could not be distracted and is experiencing severe stress, the main role is assigned to medical professional... As a qualified professional who works with infants and children younger age, the physician is obliged to take blood for analysis as quickly and painlessly as possible.

Many types of diseases can cause significant harm to a person. They don't have bright severe symptoms... Some diseases can develop into chronic ones imperceptibly. To prevent this from happening, it is recommended to go through medical examination at least once a year. Timely to recognize the onset of diseases will help and laboratory research, incl. delivery of tests such as a general clinical and biochemical blood test.