Some of the causes of a stabbing pain in your left side could include fibromyalgia, acute pericarditis or an oncoming heart attack, according to WebMD. Since the heart is located on the left side of the body, a stabbing pain on that side could indicate some type of cardiac-related issue.
Although a stabbing pain in the left side sometimes turns out to be nothing more than a trapped gas bubble or a muscle cramp, other times it can be a symptom of a much more serious ailment that requires immediate medical attention. A sudden sharp, stabbing pain that begins in the left side of the chest and travels up the arm most likely indicates a heart attack, notes WebMD.
A pain similar to this, but not as severe, also accompanies acute pericarditis, a condition caused by the swelling and inflammation of the pericardium, the thin membrane sac that surrounds the heart, explains the Mayo Clinic. Left untreated, acute pericarditis can lead to a heart attack. Fibromyalgia, a common musculoskeletal condition characterized by extreme fatigue and a decreased pain threshold, can also cause stabbing pains in the left side, although these can be attributed to the nature of this syndrome, and not any cardiac-related problems.