Will increasing the dpi of my image (without re-sampling) hurt print quality?

I'd like to start making prints, but all of my work is set at a resolution of 72. Are there any negative effects to increasing the resolution to 300? I'm very new to this, but from what I've read so far: higher res = nicer looking prints.

I apologize if a similar topic has been posted before, I just wanted to know if there was any pressing reason why I should not be doing this.