Pages is overloading cpu

Getting into 300+ of document, some text, some text boxes and a few pictures. Nothing high res. Typing is slowing down now, and the CPU is hitting 48% and higher when I type a few words. Note; some of my text is down loaded from internet and contains hypertext. I use styes to take out hypertext, but maybe it's still there, causing problems with cpu use? Otherwise I have no idea what's causing the slow down and the high temps.

Heavy MC