Hello, Thanks for posting in HCM. Yes sir your suspect is right, any lump coming up during touting of rectus abdominal muscles like when doing sit ups shows that there is some weakness in anterior abdominal wall. But however if the size is very small then it is not a matter of concern. But if you feel it is large enough or increasing in size gradually then you might need consultation of general surgeon to do a detailed clinical examination and recommend treatment after examination. Also an USG scan of abdomen can show the exact size of defect helping to plan out further line of management. So, yes it could be hernia (umbilical or paraumbilical) and it needs to be examined clinically. I hope I have answered your query well. If you have any more questions kindly directly write back to me, will be happy to help you. Thank you