Every year, your heart beats about 35 million times. We often take it for granted, until something goes wrong.
David Ward can't remember many of the miles he's logged as a commercial truck driver. But he remembers one run this spring, when he became so sick he thought it was the end of the road. "I pulled over to the side of the road and called the ambulance," said Ward. Tests showed Ward had pneumonia, but also a bad heart valve, and a bubble or aneurysm on his aorta.
If an aneurysm burst, you can bleed to death. There are often no symptoms until it's an emergency.