Things you may not know about voluntary blood donation | Why do you need to have a routine blood test before seeing a doctor?

When a child has a fever, cough, or sore throat, the doctor will write a blood test order and ask him to do it first.

During a physical examination, blood tests are usually the first item on the list;

If you are going to be hospitalized and have surgery, the first test you will have is a blood test.

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Why is a routine blood test an essential item when you are sick? Why is a blood test so important?

Blood is a symbol of life, and blood indicators are the basic indicators for doctors to diagnose. After seeing the blood test results, doctors will make the next step of diagnosis and treatment based on them.

Blood consists of blood cells and plasma. Changes in blood cell counts are an external manifestation of human health.

Red blood cells are the most numerous cells in the blood. The hemoglobin in red blood cells can combine with oxygen to transport oxygen from the lungs to various parts of the body, and take carbon dioxide from tissue cells to the lungs for excretion. The number and function of red blood cells directly affect the body's oxygen supply capacity. If the number of red blood cells is normal but the hemoglobin content is low, people will feel dizzy and weak, which is what we often call anemia. At this time, you need to find the cause of low hemoglobin. Is it due to reduced synthesis caused by insufficient nutritional intake or excessive decomposition caused by chronic blood loss? This requires further examination.

White blood cells are the body's defense system. They can identify and kill harmful bacteria and viruses. According to function and morphology, white blood cells can be divided into several categories, including neutrophils, lymphocytes, monocytes, eosinophils, and basophils. For example, in the case of the most common fever, the numerical changes of various types of white blood cells can be found through a routine blood test: if the neutrophil count increases significantly and other changes are not significant, it is basically a simple bacterial infection; if the lymphocyte count increases, it is generally a viral infection. Of course, there are also mixed infections, bacterial infections combined with viral infections, which can basically be judged through a routine blood test. Of course, if it is a blood system disease, a further bone marrow puncture examination is required.

Platelets play a key role in hemostasis and coagulation. When blood vessels are damaged, platelets will quickly gather to the damaged area to form a preliminary hemostatic plug and release a variety of chemicals to promote the activation of coagulation factors, thereby forming a more stable blood clot to prevent further bleeding. If the platelet count is low, a four-item coagulation test will generally be performed to rule out the risk of bleeding.

The human body's liver and kidney function, immune system, infectious diseases, genetic screening, etc. are also achieved through blood testing.

Doctors make a preliminary diagnosis through various blood tests and provide targeted treatment or conduct further tests.

Blood, the real source of life.

Donate blood for free, share life, share love.

(Dong Wen'an, Director of Henan Red Cross Blood Center)