Registering to be an organ donor is one of the most altruistic acts a person can make. Agreeing to give of yourself to help save someone else’s life, typically a total stranger, is generous beyond words.

Unfortunately, the need for organs in the United States greatly exceeds the supply. More than 110,000 men, women and children are awaiting transplants, and about 8,000 people die each year in the U.S. because organs are not available in time.

Organ donation agencies are constantly looking for ways to increase donations, and the results of a recent study may provide some opportunities.

Researchers at the University of California San Diego wondered if teens who are blood donors might also be motivated to register as organ donors. The thinking was that this population already understands the need to help others and have done so.

In California, anyone 17 years and up can donate blood; those 13 years or older can register as organ donors. The team visited four high schools in geographically and socioeconomically distinct areas and approached students randomly with a short questionnaire.

Of the nearly 2,000 students who participated, around half were blood donors, but only a quarter were registered as organ donors. Among those who did not donate blood, a much smaller number were registered as organ donors.

Here’s where the opportunity for increased donations comes in: Among the blood donors who had not registered to donate an organ, more than half said they were willing to sign up.

Tapping into the good graces of people already inclined to help others might just be a way to get more lifesaving donations for people in dire need.