Mac running slow - Not loading web pages
Something is wrong with my Mac. Out of the blue, over the last few days, it is running extremely slow. Web pages won't load or if they finally do it takes forever. The little spin wheel just keeps going. Sometimes a page will load after a very long time but as I scroll down, only part of the page is there and the rest never loads. I'm on a wireless connection. My husbands PC and my iPad are working just fine so it's not the connection. Any thoughts on what is wrong and how to fix it? Have not made any changes to my computer. No new software, updates, etc.
iMac, OS X Mountain Lion (10.8.4)