Heart disease refers to a range of conditions affecting the heart, including coronary artery disease, arrhythmias, heart failure, and congenital heart defects. It is a leading cause of death worldwide, often resulting from factors like high blood pressure, smoking, diabetes, obesity, and poor diet. Early detection and lifestyle changes play a key role in prevention and management. Diagnostic tools like ECGs, echocardiograms, calcium scoring, and coronary CT scans help identify heart issues before symptoms worsen. Treatment may involve medications, lifestyle changes, or procedures like stenting or surgery. Managing heart disease effectively can significantly improve quality of life and longevity.