Why does my laptop screen glitch?!

[ShingekiNoGoreyDemise]

Whenever I'm on my laptop, a bunch of white lines appear on the screen.
Then flash flash, the screen brightens and glitches out. The mouse and keyboard still respond. But the screen is glitching.

 

[Hamperking68]

Hi, By the sounds of things you may have a loose display cable.

Could you please provide with some more information about the laptop such as the Model and Make

 

[ffg7]

if you have or can borrow an external monitor to see if it does same or not.