It could be many things. It could be from slouching or sitting in a way that is causing the diaphragm to be compressed. Do not try to over straighten, just think of relaxing the muscles and allowing yourself to fall into a natural position. It could be injury from working out and doing crunches or other movements. It could be a stomach ulcer.
Another option is to blanch green beans quickly. Blanch your green beans by boiling them for 3 or 4 minutes. This removes the skin of your green beans. You want your beans to be somewhat tender, yet have a little bit of crispness to them. Determine the crispness, by how long you boil them.
Cut green beans to fit inside pint canning jars. Place green beans in a steamer over 1 inch of boiling water, and cover. Cook until tender but still firm, for 3 minutes. Plunge beans into ice water. Drain well. Pack the beans into four hot, sterilized pint jars. Place 1 clove garlic and 2 sprigs dill weed in each jar, against the glass.