Every once and a while I will start having sleep problems that are usually weird sleep schedules or weird amounts of sleep. For instance, Tonight It is 3:40 AM and I am usually in bed by 12. The night before I fell asleep at 10:30 PM can anyone explain why this happens or how I can fix it. My other question is lately I have been sleeping for small amounts of time. Last week I fell asleep at 1:30 am and woke up at 4:30 am. I wasn't tired and was able to stay awake and active without any problems with being tired and fell asleep at 12:00 am that day. A few days later I slept for over 12 hours and woke up very exhausted and was barley able to get through the day. What causes this. Almost forgot to mention that I wake up sweating some times. It can be a normal night of sleep or a short amount of sleep.