In CHF your heart beats don t effectively pump your blood. The back up of blood that isn t getting completely pumped around the body builds up causing ed em(which is a collection of fluid). This edema is often seen in the ankles and such, but the fluid can build up in the lungs which makes it hard to breath causing patients to be short of breath often. As for your husband s kidneys there could be many reasons to check them. For one the fluid needs to go someplace and your lungs is not where you want it so the doctor needs to make sure his kidneys are working properly to help filter out some of the fluid. The doctor also wants to make sure the kidneys are in proper working condition because if they are not doing their job in the first place this could also be a cause of your edema. Also diuretic drugs such as Aldactone (spironolactone), Dyazide (triamterene), Hydrodiuril (hydrochlorothiazide), Lasix (furosemide), and Maxzide (triamterene) help remove excess fluid from the body. You want to make sure the kidneys work properly before giving these drugs because it is unsafe to take these if you are unable to urinate properly. Remember also you have the right to know what is going on, and the doctors have to answer your questions so stand up for your self and be aggressive if you have to when it comes to getting your questions answered. Also if you don t understand the answers the doctors give you then ask them to explain more and don t let them get away until you understand everything that is going on. Don;t say yes you understand if you really don t make them make you understand their job is to take care of you, and understanding the situation is one of the most important steps to deciding on your treatments. Many prayers for you and your husband.