I stopped googling symptoms as it can be very scary. I was curious about the way I was feeling a few years ago (tired, body aches, lack of concentration and some IBS) and because I suffer with anxiety from time to time it tapped into my anxiety and I became almost convinced I was seriously ill despite tests showing no medical problems. Luckily I got my anxiety under control and eventually the physical issues went away by themselves, leaving me to conclude it was mostly in my head! I know this may be unrelated but like most have said a Doctor has the luxury of tests to be totally sure.
Its almost in our nature sometimes to look for the worst possible scenario based on symptoms even if the website you visit lists many possibilities, some easily treatable and non life threatening..