Hello thank you for trusting HCM Dear a sharp, aching pain under your left rib cage may cause you panic because of the possibility that it is heart-related pain. While it is true that pain under your ribs on the left-hand side could be a sign of angina or another serious cardiac issue, there are other reasons for pain under your left ribs. For example, kidney disease, an enlarged spleen, heartburn, or other digestive issues can all be reasons for varying degrees of upper abdominal or chest pain on the left side of your body. possibly spleenic flexor of colon infection or diverticulitis or pancreatitis may present like this.it is difficult to say what it is until examination is done. please consult your physician he will examine and treat you accordingly. take care