Does anyone know anything about a 2 year old not sleeping?

if he is crying hysterically when he wakes up he may be having night terrors and you should not allow him to just cry it out...my daughter used to have them and no they are not fun it would look like she was awake but she was in the "terror" and i would have to get her out calm her down and get her back to sleep. You may want to talk to his doctor. with my daughter it lasted almost a year...