Clinical blood test


A visit to a doctor often ends with a referral for a blood count. On an empty stomach or not to take it, is it necessary to adhere to some diet and where will they get blood from? If you were ashamed (or forgot) to ask the doctor about it, now we will answer all these and some other questions concerning this diagnosis.

What will the clinical analysis tell the doctor?

Clinical and complete blood count (OAK)

Clinical and general blood count (UAC) are the same. This is the most common, simple, but, nevertheless, very informative study. Its results will help to accurately diagnose many serious diseases, such as anemia, inflammation, infection.

Assessing how increased (or reduced) the number of blood corpuscles in the blood, the doctor will draw conclusions about what is happening in the body, and choose treatment tactics. The analysis is inexpensive, they do it in any laboratory, errors are extremely rare, so it is assigned quite often.

Can I eat and drink before taking the KLA?

Since blood counts are directly related to food, doctors usually recommend fasting blood tests. Hand over the "material" in the morning. When you wake up, you should take care of oral hygiene. But breakfast is advised to give up. If you can not come on an empty stomach, it is recommended to refrain from eating at least two hours before visiting the laboratory.

You can not also drink tea, coffee, drinks or juices. You can quench your thirst with pure non-carbonated water, as it does not change the composition of the blood.

And what happens if you eat before you donate blood? Theoretically, this can increase the level of leukocytes. Then, having studied the answer received from the laboratory, the doctor will make the wrong conclusions about the patient's state of health. What does it threaten with? At best, you will have to re-diagnose, at worst - the wrong treatment will be prescribed.

But in reality, tight food restrictions apply to biochemistry and hormone samples. They do not apply to a clinical blood test. On an empty stomach or not, according to the doctors, it does not play a special role, the blood formula will not change critically. However, so that patients do not get confused when they can eat, and when not, they are instructed to come on an empty stomach.

What else should patients consider?

two options for taking material for a clinical blood test - from a finger or from a vein

To eliminate errors in the results of the analysis and avoid the need for re-diagnosis, it is enough to conduct such an elementary preparation for its delivery:

  • a couple of days before the analysis to sit on a diet. The restriction applies only to fatty, fried and too spicy foods;
  • on the eve of diagnosis, alcohol should not be consumed (even in minimal amounts), including low-alcohol drinks and beer;
  • a few hours before the procedure should not smoke;
  • if a person has to quickly run up the stairs before donating blood, this may affect the result. Therefore, before entering the office, it is better to sit down for 5-7 minutes and calm down;
  • you can not take the KLA, if the day before it was conducted rectal examination, x-rays or physiotherapy;
  • The quality of the blood is affected by many drugs (antibiotics, hormones, painkillers), so you should take the test after the end of their intake or before starting treatment.

Where will the blood come from?

There are two options for taking material for a clinical blood test - from a finger or from a vein. In the first case, get capillary, and in the second - venous blood. Although theoretically there are differences between them, in practice they are found very rarely.

For the collection of blood from the pads of the ring finger, special test tubes, thin glass tubes and a scarifier (a special-shaped needle) are used. Venous blood is taken with a syringe.

How to find out what the analysis showed?

How to decipher a clinical blood test? What does this or that value indicate in the result form? If health is in order, then all indicators will correspond to normal values ​​(they are indicated on the form). Deviations in one direction or another may indicate such problems:

  • low hemoglobin is evidence of kidney, bone marrow, or anemia. Hemoglobin rates are different for men and women;
  • if the platelet count lags behind, this may be a sign of poor blood clotting. An overabundance of such bodies occurs with the development of chronic inflammation or malignant neoplasms;
  • high white blood cell count - a signal of allergies, bacterial infections, poisoning or blood diseases;
  • An insufficient number of erythrocytes is noted if a chronic focus of inflammation is present in the body. The shortage of these Taurus can be the result of a long or severe illness (but not only ARD);
  • basophils increase in response to a meeting with an allergen. Their growth can also be caused by inflammatory diseases. The lack of these elements is often associated with acute infection, hormonal disruption and stress;
  • elevated eosinophil concentration - a beacon indicating a parasitic infection or infection. But such a deviation from the norm is capable of provoking antibiotics;

How to decipher a clinical blood test

  • if the value in the "lymphocytes" column is much higher than normal, this may be due to the use of painkillers or it is associated with the negative effect of a viral infection. Decrease in lymphocytes is an alarming sign. This happens during the formation of cancer tumors, a sharp decrease in immunity. This effect sometimes gives long-term treatment with hormonal drugs.

There is also such an indicator as hematocrit. In fact, this is the degree of blood viscosity, that is, a predisposition to thrombosis.

Clinical analysis has a great diagnostic value. It gives answers to the questions of what caused the infection - viruses or bacteria, whether complications have developed, how much the inflammatory process is expressed, how the immune system reacts to the disease. Do I have to starve before such a diagnosis? Overeat, of course, should not be - no less than drinking sweet tea or coffee. But if you feel that you can faint without breakfast, then you should know: a light snack in an hour or two before the analysis will not make the number of white blood cells or red blood cells much more or less and will not change hemoglobin.