The kidneys try to compensate for a failing heart by retaining more salt and water to increase the volume of blood
. This extra fluid also can cause edema. In due course, as the condition worsens over time these measures are not enough to keep the heart pumping enough blood needed by the body. Kidneys often weaken under these circumstances, further aggravating the situation and making therapy more difficult. Most patients with mild or moderate heart failure can be successfully treated with dietary and exercise programs along with the right medications. Patients with severe heart failure may eventually have to consider heart transplantation.