According to The Joe Niekro Foundation, 6 million people are walking around with a brain aneurysm and have no clue.

Brain aneurysms sometimes have no symptoms, yet if one bursts, 50 percent of people die instantly.

"There's not a lot of education out there," said Natalie Niekro, who's father, Houston Astro's pitcher Joe Niekro, died of an aneurysm in 2006.

"My father didn't have any warning signs whatsoever,' Niekro said. "He literally grabbed his head and said, 'Oh my god, I feel like my brain is bleeding,' dropped to the floor and never regained consciousness."

She started the Joe Niekro Foundation to support other families spreading awareness about signs and symptoms.

"Most importantly, what people often say is they experience the most awful headache of their life. If you ever experience that, the message is get to the ER right away, and tell them those exact words, because they will know what to do," she said.

Other symptoms can include vomiting, blurred vision and slurred speech.

If you have family history of a brain aneurysm, get screened regularly.

Niekro did and it saved her life. This past May, doctors found she had two aneurysms.

"Aneurysms can be treated if they're caught in time," Niekro said.