A white line emerge on my note 4 out of nowhere and its increasing every day.

[Sarim Huda]

first day when I saw it i thought its a scratch on the screen then its start increasing day by day and you can see this when my phone lcd is off

 

[nahoku]

Crack maybe? Have you dropped it? If you haven't backed up your data, you might do it now before the screen goes totally out... if that's where it's headed.