Your kidneys remove wastes and extra water from your blood to form
urine. Kidney failure is reduced function or complete shutdown of your kidneys.
Kidney failure is a common and serious condition in people with
advanced
heart failure. Your kidneys need oxygen-rich blood to
function properly. When heart failure causes reduced kidney function, it is
because not enough blood is being pumped to your kidneys. Blood needs to pass
through your kidneys to remove wastes that otherwise would build up in the
bloodstream. When your kidneys don't get enough blood through them, wastes
begin to build up in the body.
Some of the major causes of heart failure, such as high blood
pressure (hypertension) and
atherosclerosis, can also contribute to kidney
failure. In addition, many drugs used to treat heart failure can also affect
kidney function.
Kidney failure can make treatment of heart failure more difficult,
because certain medicines may build up in the bloodstream. Some medicines (such
as digoxin) are eliminated primarily by the kidneys.