HOUSTON --When someone faints, most of us take it lightly, but fainting can be a symptom of something much more serious. We have the latest on why you should pay attention when a family member tends to faint. Angelina Kelly used to worry when she buckled her small children into the car. She'd worry that would suddenly faint and pass out. "It was a constant worry. When is it going to happen again? Where am I gonna be?" she said. Since she was a 15, she has passed out anywhere, any time. But when it happened while driving her young children, she was terrified. That time she was lucky. She was able to pull over and call her husband before losing consciousness. "It's very scary to think what could have happened if she would have passed out and had an accident," said her husband, Scott Kelly. "It can be life threatening depending on where it happens," Memorial Hermann Woodlands cardiologist Dr. Hina Siddiqui said. Siddiqui says Angelina has neurocardiogenic syncope, where the heart stops for a brief periods. "I will just never forget waking up to Dr. Siddiqui standing over me and saying, 'Angelina, your heart stopped for 22 seconds,'" Angelina said. Dr. Siddiqui says it's often missed by doctors, as it was with Angelina, and written off as low blood sugar or dehydration. "It's very common in young, healthy people, so that's my main thing, is that to parents, if happens to your child, just have it addressed," Dr. Siddiqui said. "We thought it was just fainting, maybe a low sugar level, but this is very serious and just a real eye-opener," Scott said. Angelina got a pacemaker, which now protects her from blacking out. The pacemaker reading showed that her heart rate had dropped almost 300 times in three months. Not all of those occasions would have been dangerous, but the doctor said some of them could have been. "It's working beautifully no problems; 284 episodes but no passing out," Dr. Siddiqui said. Not everyone with this condition needs a pacemaker. Doctors say most people do well if they stay hydrated and take medication.