I have had this issue in the past with my Gateway FX Gaming laptop, and it turned out that the card itself was bad. Then, I had to decide whether or not swapping them out was worth it (a lengthy project at the time).
I still have decided what to do with it, but I would open up your box to ensure that all your cables are connected safely, and reseat any that you find. Also, make sure that the fan is properly spinning. My mother's card was FILLED with dust and lint. So, do that, and follow it up with a good clean.
You should be good if that was the case. Otherwise, check out your drivers and the structural integrity of the card itself.