Blurry text when changing to higher settings

[jackofspades2003]

I recently got a monitor capable of 144hz and 3840 x 2160 resolution. Out of the box it was at 60hz and 1080p. Obviously i wanted to change that. Changing to 144hz want a problem but everytime i change the resolution higher, the words an dimage get blurry, the desktop icons get smaller, and sometimes the window open gets bigger to the point where I can't do anything. Am I doing something wrong? How can I change this? I'm changing it through the Nvidia control panel which is what i was told to do.

 

[kanewolf]

What graphics card? What type of cable connecting the monitor and what is the model of the monitor?