Angina pectoris is chest pain caused by reduced blood flow to the heart. There are three main types: stable angina occurs predictably during exertion and is relieved by rest; unstable angina is more severe and unpredictable, possibly indicating a heart attack; and variant angina occurs due to coronary artery spasms at rest. Treatments include medications to relieve pain, prevent angina episodes, and relax arteries, as well as lifestyle changes and procedures like bypass surgery for severe cases. Future research aims to develop more effective medications and integrate digital health tools to better manage angina.