Unstable angina is a type of chest pain that occurs unexpectedly and can last longer than stable angina. It may happen at rest or with minimal physical activity and is often more severe and frequent. This condition indicates that the heart is not receiving enough blood and oxygen, which can lead to a heart attack if not treated promptly. The symptoms of unstable angina include chest discomfort, shortness of breath, and fatigue. It is crucial to seek medical attention immediately if these symptoms occur, as they may signal a serious heart condition. Treatment often involves medications and lifestyle changes to improve heart health.