The difference between a mild and a major heart attack lies in the extent of the damage to the heart muscle and the symptoms experienced. In a mild heart attack, the blockage of the coronary artery is partial or temporary, resulting in less extensive damage to the heart muscle. Despite being labeled as 'mild,' it is still a serious medical condition that requires prompt treatment to prevent further damage to the heart. A major heart attack involves a complete blockage of one or more coronary arteries, leading to significant damage to the heart muscle. Symptoms are more intense and sudden, including severe chest pain, sweating, nausea, and shortness of breath.