If put on sleep, it need restart for work and i lossed my work

Aslam u alikum, i have Dell i5 laptop with window 8.1. if i put laptop on sleep during work, then when i come back and on it for work then it did not show my work or account rather than window wallpaper, if you press button nothing will happen, then it need restart or shutdown for work but then my previous work lossed. how can i solve this sleep problem. advance thanks