obstructive sleep apnea/hypopnea syndrome
"I have used a C-PAP for about 4 years.  Before that I was on 2 liters of oxygen at night for 6 years. I always had some daytime sleepiness, but handled it with caffiene and more recently energy drinks.  The sleepiness was getting worse and I was having microsleeps during the day. Lossing consciousnesses at work for a few seconds, waking and not knowing whether it was 3 seconds or 10 minutes.  My sleep was good with C-Pap,  I thought and the doctor read the chip from it and it said it was good too. I was prescribed 150mg Nuvigil.  It was as if half of my circuit breakers were off and someone flipped them all back on.  Startling to say the least.  The first 2 days I had a low grade headache. Had to cut way back on coffee.  Miracle!"