While the Bay Area normally imports around 30 percent of its blood from outside the state, other areas have been unable to share recently due to heavy winter storms, spokeswoman Lisa Bloch said.
There is a particular shortage of type O negative blood, known as the "universal donor type," which can be given to anyone in an emergency, Bloch said.
As of Wednesday, Blood Centers of the Pacific, the region's largest blood center, had only around one-third the amount of type O negative it needs to serve local hospitals, Bloch said.
Those who want to give blood should go to www.bloodheroes.com to make an appointment.
