Heart disease is a broad term used to describe a range of diseases that affect your heart, and in some cases, your blood vessels. The various diseases that fall under the umbrella of heart disease include diseases of your blood vessels, such as coronary artery disease; heart rhythm problems (arrhythmias); and heart defects you're born with (congenital heart defects).
The term "heart disease" is often used interchangeably with "cardiovascular disease" — a term that generally refers to conditions that involve narrowed or blocked blood vessels that can lead to a heart attack, chest pain (angina) or stroke. Other heart conditions, such as infections and conditions that affect your heart's muscle, valves or beating rhythm also are considered forms of heart disease.
Heart disease is the No. 1 worldwide killer of men and women, including in the United States. For example, heart disease is responsible for 40 percent of all the deaths in the United States, more than all forms of cancer combined. Many forms of heart disease can be prevented or treated with healthy lifestyle choices and diet and exercise.