Symptoms reminiscent of the flu. A great many ailments seem to have symptoms reminiscent of the flu, and an ulcer is no exception. If you are developing an ulcer, you might feel extremely tired through the day or may run a temperature. You may also feel nauseous. However, most flues do not persist more than about a fortnight, so if these symptoms persist beyond that time, you can be sure that they are symptoms of a more serious condition. Generally speaking, a physician should be consulted for any flu-like symptoms that persist beyond ten days or so.