Researchers estimate that 95 percent of people struggling to sleep go undiagnosed despite having more than 2,500 sleep disorder centers in the U.S.
Matthew Wright suffers from REM behavior disorder, which occurs in the last phase of the sleep cycle. During REM sleep, our muscles of locomotion are normally relaxed.
"During the REM sleep behavior disorder, those muscles are not relaxed, so if the person is dreaming about fighting or running, he'll actually do the movements," said Dr. Laurence Smolley with the Cleveland Clinic Florida.
Those movements can become violent.
"Sometimes, the bed partner has to go in another bed," said Smolley. "Sometimes, the person has to sleep on the floor or in a sleeping bag to avoid injury."
Patients can also suffer from sleep walking or night terrors.
"People have been known to go out windows, walk out a front door, [or] drive a car -- even long distance," added Smolley.
"Horrible. I wouldn't even say they're dreams -- they're nightmares," said Matthew Wright. "They're terrible. They're atrocious."
"It's scary. I've had difficulties waking him up," said Joyce Wright, Matthew's wife. "One time, I had to call the paramedics because I could not get him awake. I couldn't get him out of it."
Sleep deprivation, stress, and some psychiatric medications can all cause sleep walking and night terrors.
Doctors believe REM behavior disorder may be associated with degenerative brain diseases such as Parkinson's or dementia.
"Those patients with REM sleep behavior disorder really should see a neurologist and have a brain scan with an MRI to make sure, God forbid, there's no problem in the brain that's obvious," said Smolley.
The National Commission on Sleep Disorders Research estimates that 40 million Americans suffer from chronic sleep disorders and another 20 to 30 million experience sleep problems intermittingly.