My husband can't sleep well. he slept max of 4hours on and off. what he will do.

Insomnia: A poor sleep technic perhaps. Insomnia can occur when the environment where you sleep does not facilitate this important process. Make sure you have no distractions in the room like a tv, laptop. Ipad, smart phones, books, etc. . If still having problems may consider evaluation for restless leg syndrome or depression. Exercise during the day, not at night. Check with your physician for guidance.