(Concord, NH) - The American Red Cross say not enough people are donating blood and that widespread misconceptions about blood donation may be contributing to a shrinking blood donor population.

Amanda Romney/American Red Cross

An international movement is underway to combat the trend, calling on new donors and those who have not given in a while to help ensure that blood remains available for patients.

The "Missing Types" campaign is targeting the need for types A, B and O, the main blood groups.

During the campaign, the Red Cross brand will remove those letters in an effort to get people to donate blood before the letters A, B and O are missing from hospital shelves.

To find a blood drawing near you, visit redcrossblood.org.