(NECN/NBC News: Stephanie Bell Flynt) - Post-traumatic stress disorder is a mental health problem that can occur after a traumatic event like war, assault, or disaster.
Symptoms of PTSD can be debilitating. Some patients have horrific nightmares, and some can't sleep at all.
But new research shows using a CPAP machine - the same one that sleep apnea patients use - can help relieve some of these symptoms.
"Pretty much every time I was closing my eyes, I was having a nightmare," said Master Sgt. Chuck Murray.
Murray is retired from the U.S. Air Force after 23 years of service. But the horrors of war and conflict are etched in his memory.
"You do what you have to when you're there, and it gets stored in your brain, and once you slow down and get back to a calmer environment, it's like you find a file on a computer and it starts downloading," he said.
That downloading occurs during the REM stage of Murray's sleep in the form of chilling nightmares, a symptom of the post-traumatic stress disorder he suffers.
"I'd have to take a pain pill and a sleeping pill together, to the point of being afraid that I would not wake up," said Murray.
Also diagnosed with sleep apnea, Murray is part of a study by V.A. sleep specialist, Dr. Sadeka Tamanna. In her study she found the CPAP machine used to treat apnea also significantly improves episodes of nightmares in patients with PTSD.
"We also found it is hard for the PTSD patients to use the CPAP machine because of the mask itself," said Tamanna. "They start to feel it's smothering them. It makes them claustrophobic and it makes them remember their gas masks they've used in the war at times."
But with persistence and behavioral support, Dr. Tamanna has raised compliance for using the machine to 60 percent.
"We have a variety of masks now. Some of them cover the whole face and nose. Some of them only the nose. Some of them go inside the nose, like a nasal pillow," she said.
And the terrifying nightmares have dropped sharply for Sgt. Murray.
"Now, maybe a couple times a month compared to every day," he said. "I'm very happy with where I'm at and that I served my country."