Is it dangerous if you have a stomach ulcer and don't know? so you have the ulcer but continue to live normally drink coffee alcohol advil??

A peptic ulcer is a defect in the gastric or duodenal mucosa that goes deeper in the wall. Approximately 70 percent of peptic ulcers do not have symptoms until complications such as hemorrhage or perforation occur. If you have used Ibuprofen or naproxen for long time or have family member positive for H. pylori, express your concern to the doctor who can get appropriate diagnostic test.

Yes, as bleeding, perforation or obstruction are relatively common life threatening complications, majority being treated as inpatient. Meds, such as Advil should be stopped and irritant drinks, such as alcohol or coffee should be avoided.