Why do you have to wait half a year to donate whole blood? Things you may not know about voluntary blood donation

At the free blood donation vehicle in front of the Zijingshan Provincial People's Hall in Zhengzhou, there is a constant stream of young people coming together to donate blood.

"Teacher, I want to donate blood today",

"Thank you for your kindness! Please register first. Have you donated blood before?"

“Yes.”

"When was the last time you offered it?"

“Well, it’s almost 5 months.”

"Oh, then you can't donate blood today. Please come back after 6 months. Thank you!"

"Why do we have to wait half a year? I feel fine..."

Why is the interval between voluntary blood donations six months?

First of all, the Blood Donation Law clearly stipulates that the interval between whole blood donations shall not be less than six months. China has the longest interval between whole blood donations in the world. The purpose is to allow more people to participate, and it is based on the full protection and care of blood donors.

The human body's blood cells are produced in the bone marrow. Hematopoietic stem cells are divided into myeloid stem cells and lymphoid stem cells. Myeloid stem cells differentiate into red blood cells, platelets and neutrophils, and lymphoid stem cells differentiate into lymphocytes. Neutrophils and lymphocytes are collectively called white blood cells, which are the source of human blood cells.

The donated blood contains red blood cells, white blood cells and platelets in addition to plasma. Plasma mainly contains water, inorganic salts and proteins, which can be quickly replenished through nutrients obtained from diet. The water, vitamins, proteins, fats and other substances we take in daily are digested and absorbed, stored in the liver as energy, and released when needed.

Here, let me mention the familiar terms "fatty liver, high blood lipids, high cholesterol". The cause of "fatty liver, high blood lipids, high cholesterol" is that the body takes in too much nutrition and uses too little. In this case, doctors will recommend a light diet, increased exercise, accelerated metabolism, and reduced intake.

White blood cells are the "guardians of the human body" and their normal lifespan in the body is 7-14 days. If they encounter a fight with bacteria or viruses, they will "sacrifice" at any time. Platelets, like white blood cells, also have a lifespan of 7-14 days. If the human body has traumatic bleeding, they will activate themselves anytime and anywhere and gather into clusters to stop the bleeding.

The lifespan of red blood cells is 120 days. Mature red blood cells are released from the bone marrow into the blood vessels and have been diligently carrying out the task of transporting oxygen and expelling carbon dioxide until the end of their lives. Aged red blood cells are broken down mainly in the monocyte-macrophage system of the spleen, and the iron ions after the decomposition are recycled and reused as raw materials for the production of new red blood cells.

Donating blood voluntarily is a healthy lifestyle. The current blood donation interval in my country is as long as six months, which is to protect the health of blood donors to the greatest extent possible and save non-renewable lives with renewable blood.

(Han Xiaogai, deputy chief physician of Henan Red Cross Blood Center)