Hi doc, my sister can't sleep at night and during the day she feels sleepy and fatigued. what could this be?

Life style modificat: Usually if you don't sleep at night for some reason, it's natural that you will feel tired during the day and sleepy. It's like the jet lag. We have a circadian rhythm that controls our sleep- awake pattern. First try to avoid sleeping during the day , the try to go to bed early without watching late night shows. Avoid stimulants at night, make sure you have a quiet and dark bedroom.