<s>[INST] Sometimes I feel a flipping sensation under my lower left rib cage. I will also have muscle spasms in that area. I am 48 58 and weigh 128 lbs and in good health. I had my left lower lobe of my lung removed two years ago. What could be causing these sensations? [/INST] Thanks for your question on Chat Doctor. I can understand your concern. Possibility of simple muscle spasm is more in your case. But better to rule out heart and lung related causes first because you had left sided chest complaints and lobectomy done in the past. So get done ECG and 2d echo to rule out heart diseases. If both these are normal then no need to worry about cardiac diseases. Get done chest x-ray to rule out lung causes like pleural effusion or pneumonia. If chest x-ray is normal then no need to worry about Pulmonary diseases. Take muscle relaxant for your symptoms. Application of warm water pad on affected areas is also beneficial. Don't worry, you will be alright. Rule out heart and lung causes first. Hope I have solved your query. I will be happy to help you further. Wish you good health. Thanks. </s>