They are quite a problem! Lyme disease, Rocky Mountian Spotted fever, Texas Tick fever, this Alpha Gal( looks a lot like Shingles) plus a few others. You can coat them with petroleum jelly, and they will usually back out, I have heard of using a hot knife blade. As BJ said, don't pull with a tweezers. Just recently, I saw something about a tick remover that apparently works on a suction basis, I think.
Hawkdancer