The American Red Cross is urging people to donate blood.
The organization says donations are down about 8 percent over the past 11 weeks, resulting in 80,000 fewer donations than expected.
The Red Cross says the shortfall could lead to an emergency situation in the coming weeks.
All eligible donors are being urged to roll up their sleeves, but O negative, B negative, and A negative blood donations are especially needed.
The Red Cross is also asking people to donate platelets, which help clot blood.
For more information, call 1-800-RED CROSS or go to www.redcrossblood.org.