Heart failure is a condition where the heart muscle is unable to pump enough blood around the body. It leads to a diminished supply of blood and therefore oxygen and nutrients to the organs, and a reduced ability to exercise. Symptoms include shortness of breath, swollen legs, tiredness and lethargy. Common causes may be high blood pressure, a narrowing of the coronary arteries, heart rhythm disturbances, or as a complication of diabetes mellitus. The Swiss Atlas of Healthcare shows the frequency of heart failure diagnosis during inpatient treatments. The information required for diagnosis is not available in outpatient settings.