When Patrick Geagan goes to sleep, his wife Sue knows he can change dramatically after drifting off.
Patrick has REM sleep behavior disorder, a condition in which the body refuses to go into lockdown while the brain is creating physically active dreams.
About 1.5 million people in the U.S. have the condition, and it can get dangerous.
Nicky Ouellet, a producer for MPR News' Next Generation Radio project, spoke with the couple.
Use the audio player above to hear the story.