Being acquainted or habituated with running websites, first you should follow the speed or loading time of the general site. Is it loads faster or quite slower than as usual. Slow loading websites may loose their rankings as well as loose traffic from search engines. To check loading speed there are many ways to check including the webmasters tool, Page speed extension & other tools.
But, simply and easy to test full page using Pingdom Tools with a newer version of website load time testing tool. The latest version has much improved interface and also provides detailed analysis and reports of the load time of any website. All you need to do just enter the domain name and press or hit the test now button.