What Really Happens to Your Blood After You Donate?

It’s a squeamish subject, but we all need blood...and a lot of it. In fact, every three seconds, someone in the U.S. needs it. Whether it’s for having a baby, undergoing surgery, treatments for cancer, or chronic medical conditions like anemia, blood saves millions of lives annually. But the catch is – we can only get it from each other. Which is why very altruistic people in the world donate blood. Some 6.8 million people in the U.S. alone donate every year. But where does all this blood go after it leaves your body? Does it go to the patient down the street? How about another city?

Let’s start at the post-donation stage. First, test tubes of your blood get sent to a lab to identify any infectious diseases and blood type. At the same time, your pint of blood, or unit as it’s called, goes in a giant spinning centrifuge where it’s separated into three different components; red blood cells, platelets, plasma. And each of these have a designated function. Red blood cells are what give your blood its color and contain a protein called hemoglobin which help it transport oxygen and carbon dioxide to and from your lungs. This is what’s given to patients undergoing surgery or those with low blood cell count, like anemia.

Platelets are fragments of other cells and they help your blood coagulate properly. They’re commonly used for cancer patients whose platelets have been affected from chemotherapy. And finally plasma, a yellowish liquid that’s a mixture of water, salt, and enzymes–but also antibodies, clotting factors, and proteins.