Samsung galaxy s5 duos display after receiving notification

[awahab ali]

I am using galaxy s5 from couple of weeks but recently i noticed that when i receive a message or an in app notification appears the display gets on and never turnes off or if by any chance display is turned on to see time or any notification until or unless i don't press power key to turn the display off it won't gets off on its own which is weird and phone gets hot and battery gets drained. I have checked all settings in display but couldn't find any relevant setting in display. Please help to sort this issue out