Issue with screen lines - Maybe graphic

Hello i ve got problem with this lines on screen. It is sometimes when i wake up notebook or just watching on YT videos few minutes. It could be  graphic? After click on another site and back it disepear. I ve got this PC 2 years from new. Never cleaned soft and hardware. During games it is soo hot. I ve got it still on cooling desk, never without it. I am including photo to view. Please, tell me what is the problem. I want to get it in service, 2 years will be on 8th May. Thanks