Random high cpu usage

Lately I'm having problems with random processes (or programs) having a very high cpu usage percentage, causing my macbook to get hot and the fans turn on loudly. So far it's usually been either the time machine process (backupsd or something) and safari causing this, safari usually crashes then too. Like just now, the time machine process was using way too much cpu power so I stopped it, right as I did that safari's cpu usage skyrocketed and I had to force quit it through the activity monitor. This has only been going on for the past few days and I have no idea what could have caused this. Any advice?