Hello dr, i have a heavy achy pain on my left side right under my left breast everytime after eating a meal. what could be the cause?

Multiple answers: There can be a number of things causing this from gastritis, stomach ulcers, reflux, gallbladder disease, esophageal spasm, cardiac disease, pericardial effusion....The problem is that without a proper examination, further history, and possibly testing, this online format doesn't allow for exact diagnosis of what might be happening. See a doctor. If pain gets worse follow up immediately