I was diagnosed with obstructive sleep apnea (OSA) back in 2010 and have been on a CPAP machine ever since. Prior to my diagnosis, I was convinced that I did not have sleep apnea because I did not have the "common symptoms" of it - namely falling asleep at random times during the day or at least feeling tired or drowsy. I had the opposite - insomnia. My Dr explained to me that insomnia can be a side effect of sleep apnea although it is not a very common one. Since correcting the apnea with the CPAP, I had no trouble falling asleep (until my back issues came into play, but that's a whole other deal). Also, just FYI, my first dr - a real quack - prescribed me Trazadone and Valium. They did work, but left me even more exhausted in the mornings than the symptoms of the sleep apnea did and I eventually quit taking them and found a new dr!