CHF is Congestive Heart Failure
. It is were the heart has a hard time pumping and he can have swollen legs and his legs might look a bit shiny. CHF is treatable and many people live semi normal lives with it as long as they go by doctor's orders. The doctors should explain all of this to you and him as well. Check on www.webmd.com for further information. His doctor will probably prescribe him Lasix
is he isn't already on that for the fluid retention and he'll have to watch his fluid intake and what he eats. Good Luck!