The massive heart attack that killed actress Carrie Fisher was partially caused by sleep apnea, according to the coroner's report. Doctors say people who have the sleep disorder are more likely to have cardiovascular complications. As Spectrum News reporter Katie Gibas explains, doctors say the big concern is that many people go undiagnosed.

Sandy Fermoile has been a respiratory therapist for two decades, but it wasn't until six years ago when he realized he needed help breathing.

"I snored more. I would get warm at night. I would get cramps in my calf muscles," said Sandy Fermoile, owner of Apnea Care.

Fermoile was diagnosed with sleep apnea, which is when a person's airway closes while they're asleep, preventing them from getting enough oxygen.

"You can stop breathing five times an hour, and we're not worried about it, but anything above five times per hour is when people start getting symptoms. When you get into the 15-20 range, it seems to be associated with these medical issues," said Dr. Marc Frost, the DENT Sleep Disorders Lab co-director.

Doctors say the oxygen deprivation puts extra strain on the heart and can lead to heart disease, strokes, diabetes, and hormonal imbalances. They say it also makes people with sleep apnea between two and four times more likely to suffer a heart attack and death than those without. In fact, actress Carrie Fisher's coroner's report says sleep apnea, among other things, was a contributor to the massive heart attack that killed her.

"It mainly happens during REM sleep, which is rapid eye movement sleep. The most prolonged REM sleep happens between 4-6 a.m., so we see the sudden death in these early morning hours, as well as seeing heart attacks happen during these early morning hours," said Dr. Alexander Gelfer, Kenmore Mercy SleepCare Center medical director.

And getting diagnosed early is the key to improved health and function, and doctors say one of the easiest ways to do that is a sleep study that can be done in the comfort of your own home.

"CPAP is the most effective treatment for sleep apnea, and it's nothing more than a scientific air compressor. It's just blowing air into your nose or mouth  to split your throat open. If you think of your throat like a windsock. When there's no air blowing through it, it collapses, and that's apnea," said Frost.

"I know there's a definite difference in how I feel," Fermoile said. "I don't sleep as deep without it. And there's not a clarity when I get up in the morning."

Doctors say effective treatment of sleep apnea reduces the likelihood of a heart attack back to normal risk levels.