A blood test is a general name for a group of tests that can be done by taking a sample of the body's blood, placing it in a test tube, and then performing accurate tests on it in a laboratory.
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| Blood test |
The goal of the blood test is to measure the levels of various substances in it, such as blood cell count, salt concentration, and levels of other elements that would indicate the presence of disease states, such as:
- Hemoglobin level, which may indicate anemia.
- Examination of kidney and liver functions, which would indicate a defect in the work of these organs.
- The level of sugar that would indicate diabetes.
- Checking blood cholesterol levels, etc
In addition, the function of the blood test is to diagnose various harmful factors that may be in the body, by taking a culture sample of blood and searching for various germs, viruses and other contaminants that may be present in the blood.
When is a blood test performed?
Often, a blood test is done periodically, in order to monitor the health status of the person, mainly, as this is done routinely by the doctor.
By means of these "random" examinations, it is sometimes possible to discover some different pathological conditions, for which it was not possible to notice the presence of symptoms for a long time, which allows treatment at an early stage. Mostly, blood tests that are done routinely include:
- Blood component count.
- Checking the basic chemicals in the blood.
- Checking the levels of fats and cholesterol in the blood.
- Kidney and liver functions.
In some special cases, eye blood tests are performed, in order to diagnose something that may be happening and developing in the body. The set of tests that must be performed relate to the symptoms and signs that the patient complains of, for example: a patient who suffers from a very high body temperature, he may be suffering from an infection, which calls for a request to examine the “transplant” of blood germs in addition to a routine blood test, in an attempt to identify The cause of infection.
Prepare for examination
There is no need to take any special steps in preparation for the test, but for a routine blood test, usually requires fasting for 12 hours, only water is allowed.
The reason for this is to make it possible to measure the basic and true levels, as accurately as possible, of substances in the blood, as the analysis of food and its access to the blood can lead to the presence of higher than usual levels of sugar, cholesterol or other substances. Also, it is usually okay to take medications before the examination, but it is desirable to consult a doctor in this regard.
The at-risk category
Patients who suffer from infectious diseases that are transmitted through the blood, such as hepatitis, AIDS, and others, must inform the medical staff of this before the examination.
It is true that infectious diseases do not prevent a blood test, but the presence of such diseases requires the medical staff to take more precautions and caution in order to prevent the transmission of infection.
Diagnosed diseases
It is possible to diagnose a very wide range of diseases and monitor them through a blood test, most notably the following:
- anemia.
- coagulation disorders.
- diabetes mellitus;
- Drought.
- Kidney failure.
- Inflammatory cases.
- Different types of infection.
- Liver diseases.
- blood cancer.
- Damage to the heart muscle, and others.
How to perform the examination
In general, a blood test is performed when the examinee's arm is outstretched and placed upside down on a flat surface or table. The examiner tightens a rubber band around the upper arm, in order to temporarily block blood flow in the hand as much as possible, and to confine the blood to the area from which the sample is taken by injection.
Next, the person undergoing the examination is asked to clench his hand as much as possible, a movement that helps the person conducting the examination to find the best blood vessel to take the sample from.
It is usually a vein in the elbow or forearm area. In some cases, the sample is taken from the back of the palm of the hand. When a suitable vein is found, the area is disinfected with alcohol, and a fine needle is then inserted into the vein. This needle is attached to a special test tube or syringe.
This process may not be gentle and comfortable, as it causes a slight pain when pricking. Later the person performing the test draws the required amount of blood, based on the number of test tubes (the number of test tubes required depends on the amount and type of tests the laboratory is required to perform).
When the blood is drawn, the needle is quickly removed from the vein, and then pressure must be placed immediately on the puncture site, in order to prevent blood flow from there, and the test tubes are taken to the laboratory for examination.
In some cases, two or three pricking attempts are needed, when the vein cannot be penetrated, or when the test performer cannot take the required amount of blood the first time. The patient must be patient, as this process is not always simple, but it usually takes between 5-10 minutes.
After the blood test
You can stop applying pressure to the puncture site after two or three minutes, or when the bleeding stops. In the majority of cases, there is very little internal bleeding at the site of the examination, which does not require any treatment because it disappears spontaneously within several days.
In some rare cases, it is possible to get a large painful bleeding and cause swelling at the site of the examination, which requires informing the doctor immediately in order to make sure that there is no infection in the area of the vein (phlebitis) may require treatment by applying hot compresses several times a day .
The high risk associated with blood tests, is related to the examination with a contaminated needle. Therefore, blood tests should be refrained as much as possible in third world countries, and in other regions of the world where hygiene and sterilization rules are not fully stressed.
Warnings
general
There is a very small risk of having a complete blood test and you may feel slight pain or bruising where the needle was inserted, but most of these symptoms usually go away quickly.
Analysis of the results
Often, within a day or two, the results of a periodic blood test appear as a list. However, there are some types of special eye exams that may need a longer time.
The results form on each line contains the item level that the patient has checked against the normal levels that should be, allowing comparison between the two values and usually stressing about results outside the normal range.
It should be noted that there may be laboratory errors in some cases or the possibility of results that are significantly outside the normal range, and inconsistent with the real patient's situation, which calls for re-examination.