Describe the illnesses the three friends fancy they aresuffering from?

From the text:

Harris said he felt such extraordinary fits of giddiness come over him at times, that he hardly knew what he was doing; and then George said that he had fits of giddiness too, and hardly knew what he was doing.  With me, it was my liver that was out of order.  I knew it was my liver that was out of order, because I had just been reading a patent liver-pill circular, in which were detailed the various symptoms by which a man could tell when his liver was out of order.  I had them all.