<s>[INST] When I lay back on an exercise ball to do my ab crunches, I can feel a "ridge" like a mountain range going up and down the middle of my abdomen.  It seems to be growing and has started pushing out my belly button (which has always been an "innie").  I have been about 50 pounds overweight for years, but this is different...it looks and feels different.  Could it be some type of "fat tumor"...or is it just plain fat?  Should I be concerned? [/INST] Hi ! Good evening. i am Dr Shareef answering your query.If I were your doctor, I would not opine on your condition without getting you examined clinically specially your abdomen. What you have described could simply be a hernia, or any intra abdominal condition. To know the exact status of your condition, you need to be examined clinically preferably by a surgeon along with any special investigations like an ultrasound/CT scan as suggested by him to support his clinical findings. Therefore, I would at present suggest you to get your self assessed first by your family physician, and by a general surgeon if considered necessary by him.I hope this information would help you in discussing with your family physician/treating doctor in further management of your problem. Please do not hesitate to ask in case of any further doubts.Thanks for choosing health care magic to clear doubts on your health problems. Wishing you an early recovery. Dr Shareef. </s>