I have a hard mass/lump under skin above belly button.  In addition, when I walk I lean to the left.  Everyone is asking if I am okay.  Dont know if its related to whatever is under my navel.  It is more noticable when I am standing, and I arch my back.  What would be the signs of a hernia vs a tumor?
Welcome to Chat Doctor .1. The history suggest most possible cause could be umbilical hernia.2. If you are my patient I would have examined and ask for the ultrasound abdomen.3. Ultrasound will help to evaluate the nature of the lesion (solid, cystic, mixed) in case of mass lesion, and its sours and extensions.4. In case of hernia the defect will be evaluated and herniating content will be scanned (bowel, momentum) at to assess weather there is any strangulation and vascularity Wii be checked.5. So I would suggest you to take an appointment and get the needful investigations and treatment done. Good luck. Hope it helps you. Wish you a good health. Anything to ask ? Do not hesitate. Thank you.