Congestive heart failure, known as CHF, is an inadequate pumping function of the heart. When the heart is not pumping at capacity, proper circulation of blood fails. Subsequently, the build-up of blood and fluid leads to the development of congestion and excess watery fluid in the lungs and other tissue. How quickly heart failure develops is dependent on whether it involves the left, right, or both chambers (ventricles) of the heart. CHF often includes various combinations of the following signs and symptoms: shortness of breath; skin indention such as that created from socks or stockings; an enlarged, tender liver; swollen neck veins; and abnormal lung sounds. Approximately 3 million people in the United States have been diagnosed with CHF and greater than 400,000 new cases are reported annually.