I read if you have more than one or two yeast infections a year it could be something seriously wrong how can you tell and stop the problem?

Maybe: Yeast is a normal organism found vaginally. A yeast infection occurs when the yeast "over grows" due to some change in the vaginal environment. Antibiotic use is the most common reason for this change. Diabetes is another (more serious) reason. See your family doctor or gynecologist if thaws infections are frequent.

Medical checkup time: Occasional yeast infections in mouth or vagina are common after using antibiotics & resolve spontaneously or with brief anti-fungal treatment. Persistent or recurrent yeast infections especially without obvious cause require evaluation as they suggest a weakening of your immune system. Your primary care physician should see you and begin the evaluation.