While driving a vehicle if we come across a big pit on the main road, we go ahead by a new route from the side and join the main road again after some distance. The same is done in the coronary arteries. An artery or a vein is harvested from the body and its proximal end is joined with the aorta, while its lower end is joined with the same coronary artery distal to the blockage. Thus, the blockage in the coronary artery is bypassed in this process. By doing so, the blood from the aorta passes through the newly inserted/ grafted bypass route and reaches to the main coronary artery distal to the block. With the restoration of blood supply to the heart, the patient gets relieved of his symptoms of angina and shortness of breath and the efficiency of a heart also improves. Scientific research has proved that not only the quality of life of a patient is greatly improved but lifespan also lengthens after a good bypass surgery.