Is a lump bigger than golf ball protruding from navel always a hernia and is it ok to ignore?adam

Not always.: Your description fits a fair number of "differential diagnoses" (possible medical conditions). The information needed to confirm or rule out each possibility include: symptoms, changes in function of different organ systems, physical examination, labs and radiologic studies. Some of the possibilities are quite serious, so i think it is not ok to ignore. See your dr. Good luck.

Not always: Never say always. It is probably a hernia, and should be examined by your primary care provider. Together, you can determine whether it not it needs any testing or a referral to a surgeon.