Digoxin is used to treat congestive heart failure and to treat certain types of abnormal heart rhythms. It helps to reduce the symptoms of congestive heart failure (e.g., swelling in the ankles, feet, and hands; shortness of breath; frequent fatigue) by helping to increase the strength of the heart so that it pumps more efficiently. Digoxin also helps to maintain a normal heart rhythm in patients with atrial fibrillation.