You toss and turn all night, legs are restless, pulling out the hair why just cant fall asleep. There is a saying in Chinese classical text:”when stomach is unsettled, sleep is disturbed”. Another cause is the Yin and yang are not communicating, when the yang needs to travel back to yin at night so that you can fall asleep. But when the sun is shining at middle of night, it is very difficult to fall asleep.