Heart failure occurs when the heart is unable to pump blood effectively, leading to inadequate circulation and oxygen delivery to the body's tissues. This condition can result from various cardiovascular issues, such as coronary artery disease or hypertension. Symptoms include shortness of breath, fatigue, and swelling. Heart failure may be chronic or acute, requiring medical intervention, lifestyle changes, and, in severe cases, heart transplantation. Early detection and management are crucial for improving quality of life and prognosis.