I seem to have a sleep disorder where I am waking up at odd hours. Sometimes at 1 am, sometimes at 3 am sometimes at 4 am. As a result I am not able to get full sleep of at least 6 hours per day. In the past this was the time when my mind used to switch from normal sleeping mode to dreaming mode. This used to happen automatically. However from past 3 months this is not happening and I am unable to sleep after waking up at odd hours. How can I solve this problem. However even though I sleep for around 3-4 hrs I am fresh and relatively fine through out the day.