SOUTH BEND — Hospitals and paramedics rely on blood donations when there's an emergency. But when you give, where does it go?

Jack Lloyd of Buchanan has a Good Question: “I donate blood on a regular basis to the South Bend Medical Foundation. I was wondering where does it end up getting used, and how does it help people?"

WSBT's Kirk Mason looked into it.

Every day at the South Bend Medical Foundation’s two locations, people donate blood. The process takes about 45 minutes from the time you check in.

After you donate blood, it then runs through a gravity filter that removes white blood cells. From there it's on to a centrifuge, which separates red blood from plasma and plasma from platelets.

Ninety percent of your donated blood stays in St. Joseph County. Some also goes into nearby surrounding counties. But in rare cases — emergencies — your blood can go anywhere across the country.

“We work with what's called the National Blood Exchange,” explained Dr. Bobbie Sutton of the SBMF. “Where hospitals all over the United States, when they have a pressing need for a patient's product, and any blood center around the county can say, ‘Oh you need O-positive? We’ve got O-positive.’”

As for what your blood is used for, it can be used during a terrible trauma to try and save lives, but most often it's something else.

”A lot of our blood products go to open heart patients,” Sutton said. “That is a particularly high use because of the type of surgery. A lot of it goes in support of cancer.”

Only 5 percent of people who can donate blood do, and donors can do it again every 56 days.

The South Bend Medical Foundation has two locations, one downtown near Memorial Hospital, and the other in Mishawaka near Edison Lakes. You don't have to make an appointment to donate.