Mayo Clinic Radio: American Heart Month According to the American Heart Association, heart disease is the No. 1 killer in America, causing 1 in every 4 deaths each year. Heart disease includes a wide range of conditions that affect your heart, including blood vessel diseases, such as coronary artery disease; heart rhythm problems; and problems with the heart valves or heart muscle itself. Heart disease can be improved — or prevented — by making certain lifestyle changes, including quitting smoking, controlling your blood pressure and cholesterol, and staying at a healthy weight and getting regular exercise. In an ongoing effort to raise awareness and promote prevention of heart disease, each February is recognized as American Heart Month.