Plasma, which is 90 percent water, makes up 55 percent of blood volume. Healthy bone marrow makes a constant supply of red cells, plasma and platelets. Blood or plasma that comes from people who have been paid for it cannot be used to human transfusion. Granulocytes, a type of white blood cell, roll along blood vessel walls in search of bacteria to engulf and destroy. White cells are the body's primary defense against infection. Apheresis is a special kind of blood donation that allows a donor to give specific blood components, such as platelets.
Forty-two days: how long most donated red blood cells can be stored. Five days: how long most donated platelets can be stored. One year: how long frozen plasma can be stored. Much of today's medical care depends on a steady supply of blood from healthy donors. Three pints: the average whole blood and red blood cell transfusion. Anemic patients need blood transfusions to increase their red blood cell levels.
Cancer, transplant and trauma patients, and patients undergoing open-heart surgery may require platelet transfusions to survive. Sickle cell disease is an inherited disease that affects more than 80, people in the United States, 98 percent of whom are of African descent. Many patients with severe sickle cell disease receive blood transfusions every month. A patient could be forced to pass up a lifesaving organ, if compatible blood is not available to support the transplant.
Thirteen tests 11 for infectious diseases are performed on each unit of donated blood. Seventeen percent of non-donors cite "never thought about it" as the main reason for not giving, while 15 percent say they're too busy. The number one reason blood donors say they give is because they "want to help others. Blood centers often run short of types O and B red blood cells. The rarest blood type is the one not on the shelf when it's needed by a patient. There is no substitute for human blood.
If all blood donors gave three times a year, blood shortages would be a rare event. The current average is about two. If only one more percent of all Americans would give blood, blood shortages would disappear for the foreseeable future. Four easy steps to donate blood: medical history, quick physical, donation and snacks. The actual blood donation usually takes about 10 minutes. The entire process - from the time you sign in to the time you leave - takes about an hour.
After donating blood, you replace the fluid in hours and the red blood cells within four weeks. It takes eight weeks to restore the iron lost after donating. You cannot get AIDS or any other infectious disease by donating blood. One unit of whole blood is roughly the equivalent of one pint.
Blood makes up about seven percent of your body's weight. A newborn baby has about one cup of blood in his body. Giving blood will not decrease your strength.
What Is Whole Blood? What Are the Components of Blood? Schedule an appointment. Why Donations Are So Important Recent studies show that there is a need for blood transfusions every 2 seconds. Learn More About Blood Components. Learn More. According to a article , there are around For clarity, Medical News Today has converted these figures from the formula given in Open Anesthesia.
There are different ways of testing, but a blood volume test usually involves injecting a small amount of a tracer substance into the body. A healthcare professional will then use imaging technology to track blood moving around the body. According to the American Red Cross , the standard amount of blood a person will give during a blood donation is 1 pint. A person may feel a little faint after donating blood, and so donation centers ask donors to rest for 10—15 minutes and take some refreshments before leaving.
If a person has an illness or accident, they may lose more blood. This can lead to shock, and it can be life threatening. Donating blood can save lives, but how does it affect the donor? Severe bleeding can be dangerous. In medical terms, shock means that not enough oxygen is reaching tissues in the body. Low oxygen levels can cause damage to the brain and other organs. If someone is losing blood, the body will start to direct blood toward the vital organs and away from the skin, fingers, and toes.
A person may begin to look pale or feel numbness in their extremities. If they lose more blood, they will start to feel confused. Their blood pressure may rise to around beats per minute bpm , as the body tries to maintain blood supply to the vital organs. Their pulse rate will rise over bpm. They will feel lethargic and may lose consciousness. External bleeding : Head wounds or a deep wound or a cut on or near a vein, such as on the wrist or neck, can result in severe blood loss.
Internal bleeding : An internal injury, such as a blow to the abdomen, can lead to a sudden and significant loss of blood, but this may not be visible from the outside. The clinical review in Critical Care indicates that medical conditions, such as a perforated ulcer, lung cancer , or a ruptured ovarian cyst, can also cause internal bleeding. Depending on where internal bleeding occurs, bruising may start to appear.
There may be a loss of blood through the mouth, nose, or other orifices. Learn the difference between an artery and a vein here.
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