I've developed ganglion cysts on and off over several decades. With one exception, they've gone away on their own. When I developed cysts on the up side of my wrist I found that wearing a wrist band for immobilization helped a lot. It reduced pain significantly and, I believe, speeded the diminishment of the cyst. I've also had the fluid removed from some of them -- effective method if they're large enough for a doctor to find with the extraction needle. I asked my doctor about the old-time method of slamming cysts with a telephone book. She said that in some cases the treatment actually worked, but since doctors now know that some cysts "shatter" and form many new cysts from the remnants, this treatment is no longer recommended.