Hello doctor.. My son is 2yrs 2month from past 2 to 3 weeks he is not sleeping bat night.. from 10pm till 4am we keep trying and at last he sleeps aft 4am..he used to sleep before at night very well. but from past few weeks he is not sleeping at night.. even if he stays awake whole day, he sleeps in early morning.. aft sleeping he gets up at afternoon 1 and then he doesn't sleep.. I am bit worried about this change in his sleep pattern.. kindly guide..