For some blood donors, giving is an old habit.

What donors know should inspire more people to give. But sadly, there’s a lack of people simply showing up.

According to University Health System, only 10 percent of people eligible to donate actually do. As a result, supplies in South Texas are critically low.

All blood types are needed but type O is especially valuable.

And while blood is needed, it’s important to know that not everyone can be a donor. Medical experts suggest speaking with a doctor or screener before getting in line to give.