<s>[INST] I have been about 50 pounds overweight for years, but recently when I lay back on the exercise ball to do my ab crunches, I can feel a "ridge" like a mountain range running up and down inside my abdomen area.  It seems to be growing and has started to push out my belly button (which has always gone "in").  I am wondering if this could be some sort of "fat tumor" or is it probably just belly fat?  It feels different than just the fat I have become used to over the years.  I have never felt anything like it.  The "ridge" is definitely very obvious to feel and find.  Should I be concerned? [/INST] HI.Thanks for your query.Nice explanation to make a diagnosis on clinical history alone. This looks to be a Hernia as it rises on increases intra-abdominal pressure. If the ridge is too long this can be due to divarication ( separation) of the recti muscles from each other - this is also as bad as a hernia.No this may not be a fat tumor.The best way is to get this confirmed by clinical examination by a Surgeon and to plan. If this is hernia- a prolene mesh repair will help to block of this protrusion. </s>