Preparing for blood tests

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Blood counts can change significantly throughout the day, so it is recommended to take tests in the morning. For this period, reference intervals for many laboratory parameters have been calculated. This is especially important for hormonal studies.

All blood tests are done before radiography, ultrasound and physiotherapeutic procedures.
Do not smoke 2 hours before donating blood.
For 2-3 days, do not overeat, especially fatty foods, avoid alcohol, intense physical activity, and also do not visit the bathhouse or sauna.

Food restrictions:

On an empty stomach: at least 4 hours after the last (not large!) meal.
Strictly on an empty stomach: at least 8 hours after the last meal. In newborns and children in the first months of life, blood sampling is allowed no earlier than 2 hours after eating.
Fasting: no food intake for at least 12-14 hours.
Drinking regime . Drinking water does not affect blood counts, so drinking water is allowed (not mineral, non-carbonated). Juice, tea, coffee are prohibited.

How to suspect deterioration of coagulation hemostasis

The first signs indicating poor blood clotting

Prolonged bleeding occurs with minor skin injuries or after injections. Normally, cuts or injections should not bleed for more than 3-5 minutes, but if there is pathology, this time can increase significantly. Sometimes such people have hemorrhages under the skin.

Another symptom that indicates this condition is prolonged nosebleeds that are difficult to stop. Women with hemocoagulation disorders may experience menorrhagia and metrorrhagia. Sometimes traces of blood may even be present in urine and feces.

If these symptoms appear, it is recommended to donate blood for a coagulogram. Research conducted by our specialists will help identify disorders of coagulation hemostasis. All analyzes are carried out using modern equipment and reagents.

Hormones

Blood collection is carried out strictly on an empty stomach: at least 8 hours must pass from the last meal (preferably at least 12 hours). You are allowed to drink water (non-mineral, non-carbonated). It is forbidden to drink juice, tea, coffee. 2-3 days before the test, do not overeat, especially fatty foods. Avoid alcohol, intense physical activity, and do not visit the sauna or bathhouse.

On the day of blood collection, avoid taking medications; if withdrawal is not possible, inform the laboratory.
When studying hormones over time, it is advisable to take blood samples at the same time of day.
Some hormones need to be taken by women on certain days of the menstrual cycle. This information can be obtained from your doctor.

Attention!Q Blood collection for cortisol is carried out strictly on an empty stomach, strictly in the interval from 8:00 to 11:00 (the exact time of venipuncture is indicated).

Decoding the result

I. Quick's prothrombin, prothrombin time, and international normalized ratio (INR) reflect the activity of the extrinsic coagulation pathway.

Prothrombin time
is the time of blood clotting after the addition of substances (thromboplastin with calcium) to the plasma that trigger the extrinsic blood coagulation pathway. Time is measured in seconds (sec.). The longer the prothrombin time, the lower the activity of coagulation factors.
Prothrombin according to Quick
is considered a more objective indicator of the external pathway, since during the analysis the clotting time is studied depending on the different concentration of coagulation factors in the blood obtained by diluting the test material in the laboratory. The indicator is measured as a percentage (%). The longer blood clotting occurs, the lower the Quick prothrombin percentage.
The international normalized ratio (INR)
is a prothrombin test standardized in accordance with international recommendations. It is calculated using a certain formula. The higher the INR, the longer it takes for a blood clot to form.

Prothrombin time, prothrombin according to Quick and INR with normal fibrinogen content and activity also reflect the activity of the prothrombin complex (II, V, VII, X blood coagulation factors).
When prescribing therapy with anticoagulants from the group of vitamin K antagonists (warfarin), there is an increase in INR and prothrombin time and a decrease in prothrombin according to Quick. Other causes of these changes may be vitamin K deficiency (for example, with hemorrhagic disease of the newborn), hereditary deficiency of factors II, V, VII, X, liver and intestinal diseases. The opposite picture, i.e., a decrease in INR, a decrease in prothrombin time and an increase in prothrombin according to Quick, occurs in conditions accompanied by increased blood clotting: thrombosis, blood thickening during dehydration, when taking oral contraceptives, barbiturates.

II. Activated partial thromboplastin time (aPTT)

with normal content and activity of fibrinogen, it characterizes the internal pathway of blood coagulation, which includes the activity of factors II, V, VIII, IX, X, XI, XII. APTT is determined by adding reagents that trigger this clotting pathway to a blood sample and measuring the time it takes for the blood to form a clot. Measured in seconds (sec.). The slower the blood clotting, the longer the APTT.

This indicator is used to monitor therapy with heparin (direct anticoagulant), and an increase in the aPTT value is noted. Other causes of increased time include hereditary and acquired deficiencies of intrinsic pathway coagulation factors, for example, in hemophilia, hemorrhagic disease of the newborn, liver and intestinal diseases, some autoimmune diseases, etc. The reasons for increased aPTT are the same as for Quick's prothrombin.

III. Thrombin time and fibrinogen reflect the overall, or final, pathway of blood clotting.

Fibrinogen
is blood clotting factor I, a protein synthesized in the liver and converted into fibrin, the basis of the clot during blood clotting. It is also an acute phase protein. It is measured in grams per liter (g/l). With increased thrombus formation and various inflammatory diseases, the synthesis of this protein increases. In case of liver diseases, hereditary fibrinogen deficiency, etc., its concentration decreases.
Thrombin time
is the blood clotting time necessary for the formation of a fibrin clot when thrombin is added to the plasma - an enzyme (factor IIa), which appears when blood coagulation factors interact when a vessel is damaged. Thrombin time depends on the level and activity of fibrinogen. Measured in seconds (sec.).

Changes in thrombin time generally correlate with fibrinogen levels. However, with such a hereditary disease as dysfibrinogenemia, i.e., a violation of the functional activity of fibrinogen, an increase in thrombin time and a coagulation disorder occurs, despite the normal amount of fibrinogen in the blood.

Glucose tolerance test

Attention: A glucose tolerance test is prescribed only after consulting a doctor. This study is not performed for patients with type 1 diabetes mellitus.

Blood collection is carried out in the morning, after fasting: at least 12-14 hours must pass from the last meal.

Before performing the glucose tolerance test, follow a diet for 3 days (no more than 150 grams of carbohydrates per day), exclude intense physical activity, and do not visit the bathhouse or sauna.
3 days before the test, stop thiazide diuretics, contraceptives and glucocorticoids (in consultation with your doctor).
Do not drink water or smoke during the study. Repeated blood sampling is carried out 1 hour and 2 hours after the “load” of glucose.

Normal indicators

Index	Reference value	Unit
Prothrombin time	9,0–15,0	sec.
Prothrombin according to Quick	78–142	%
INR	depends on the presence of concomitant pathology in the patient for which he receives anticoagulant therapy
APTT	25,4–36,9	sec.
Thrombin time	10,3–16,6	sec.
Fibrinogen	2,00–4,00	g/l
Fibrinogen	up to 5.6 (2nd and 3rd trimester of pregnancy)	g/l

Preparing for a thyroid-stimulating hormone (TSH) test

TSH levels are the most sensitive test for assessing thyroid function. However, it remains the most frequently deviating from the reference interval among all hormonal studies. To obtain reliable results, in addition to the general rules for preparing for laboratory tests, it is important to follow the rules below:

The TSH level changes significantly during the day: its highest concentration is determined in the morning, and its minimum in the evening. You should donate blood at the same time, especially in case of repeated tests, since the time of blood donation plays an important role in the interpretation of the TSH level.
In the case of thyroid hormone replacement therapy, it is necessary to take the drug after drawing blood for testing. Taking thyroxine and iodine the day before the test does not affect the TSH concentration. It is advisable to carry out repeated studies of TSH levels in order to monitor therapy no earlier than 6 weeks after changing the dose or type of drug.
It must be remembered that the TSH result may be distorted by the effects of medications taken or the products of their metabolism. Before donating blood for analysis, you should consult your doctor about the possibility of limiting the intake of medications during the period of preparation for the study. It is recommended that you stop taking medications, including dietary supplements, before the study. If it is impossible to stop taking medications, you should provide the name of the drug and the time of its last use when donating blood.
The thyroid gland is associated with the work of many organ systems, disorders in which can affect the secretion of the hormone: acute and chronic stress, acute infectious diseases, disorders of lipid and vitamin metabolism, leading to excess cholesterol, homocysteine, as well as disturbances in sleep patterns and wakefulness at night, which disrupt the normal rhythm of TSH secretion. The influence of these conditions must be taken into account when interpreting the results if it is not possible to postpone the study to a later date.
Different research methods may be used in different laboratories, therefore, in order to correctly evaluate the research results, it is necessary to conduct research in the same laboratory and on the same analytical system.

Coagulogram (screening)

No. OBS103Comprehensive studies

Hemostasiogram (coagulogram), screening A basic set of tests used for screening assessment of the state of the blood coagulation system.

Up to 1 business day

RUB 1,360 Add to cart

No. OBS109Comprehensive studies

Hemostasiogram (coagulogram) extended This set of tests is used for a detailed assessment of hemostasis disorders: if thrombophilia is suspected, the risk of developing thromboembolism and/or disseminated intravascular coagulation (DIC), or the patient’s severe general condition.

Up to 1 business day

RUB 3,790 Add to cart

You can take a coalogram at the nearest INVITRO medical office. A list of offices where biomaterial is accepted for laboratory research is presented in the “Addresses” section.

The blood coagulation system is primarily an enzymatic system that provides external, internal and general coagulation pathways. These mechanisms are successively replaced, but they can also occur independently of each other.

The screening coagulogram includes the following indicators:

prothrombin (prothrombin time, prothrombin (according to Quick), INR - international normalized ratio);
fibrinogen;
APTT (activated partial thromboplastin time);
thrombin time.

These indicators are basic and allow you to evaluate all coagulation pathways.

Complexes with this research

Female infertility Analysis of the state of women's reproductive health 16,210 ₽ Composition
Pregnancy planning. Clinical indicators 6,630 ₽ Composition

Extended coagulogram Extended study of the functional state of hemostasis 4,150 ₽ Composition

IN OTHER COMPLEXES

Miscarriage RUB 40,070
Joining IVF RUB 23,020
Examination during pregnancy. 3rd trimester 9,620 RUR
Coagulogram RUB 2,020
Examination during pregnancy. 1st trimester 16,690 RUR