Could you tell me what happens if you leave a yeast infection untreated?

Your own discomfort: A yeast infection commonly causes itching and redness, so that is the worst. However sometimes women think they have a yeast infection but actually have something else, so if it doesn't go away on its own it is wise to get checked. Yeast infections can be treated with over the counter meds. If you don't want to take a med stop all sugar, carbs, fruit, alcohol. Can try yeast arrest.