Left heart failure occurs when the left side of the heart cannot pump blood effectively to the rest of the body. This can lead to a buildup of fluid in the lungs, causing symptoms like shortness of breath, fatigue, and coughing. It often results from conditions such as coronary artery disease or high blood pressure. There are two main types of left heart failure: systolic heart failure, where the heart muscle is weak and cannot contract properly, and diastolic heart failure, where the heart muscle is stiff and does not fill with blood adequately. Both types can significantly impact a person's quality of life and require medical management.