Severe pain in left upper abdomen including under ribs and pain in left ribcage on side. how can i deal with this?

Hard to say: There are multiple potential causes, you should consider being seen. Possible causes can incude an irritation of a nerve in the thoracic spine, an inflammatory condition involving the pancreas or the lining of the lung, and multiple other causes. A detailed exam and appropriate studies can usually sort out the cause. Thank you for the question.