I'm usually used to taking a nap and my dad would be on the couch or somewhere napping also. Today though was different. My dad has sleep apnea so I get worried enough when he sleep without the apnea device to help him breath. Today or tonight my dad is in the arm chair and I'm in the other I took a while to fall asleep just listening to him breath. After falling asleep I thought it was my imagination but I woke up out of my sleep to my dad making a long suffocating noise, just a long groan, picture someone regular sleeping and they just have a silent scream in their dream but in reality it's just them making a small yell but more suffocating than normal. I was so scared that I called out to him immediately. Seeing him wake up the noise stopped immediately and I knew it was him. I want to know why he made that sound he has never just suddenly had small suffocating groans like that. Could his apnea be getting worse?