My cat is ripping her fur out and peeing everywhere, help!?

If it is a medical problem, only a checkup and tests will detect what is wrong. My friends cat started doing that toward the end of his life. They spent thousands of dollars on the cat, and tried many different medicines for thyroid, skin problems, etc. He ripped out all of the fur he could get his mouth on. He peed everywhere, and near the end he would meow while he was peeing like he was in pain. He got really bad and was in constant pain and had to be put to sleep.