A yeast infection is an overgrowth of yeast — usually the fungus Candida albicans — in the vagina, mouth (thrush), intestines, or skin folds, causing itching, irritation, discharge, and swelling. Candida lives harmlessly on most people in small numbers; it overgrows when antibiotics, high blood sugar, hormonal changes, or weakened immunity disturb the balance. Treatment is with antifungal medicines, and prevention means addressing the underlying trigger — blood-sugar control in diabetes, for example. Diet claims around candida overgrowth abound, but the evidence for anti-candida diets is thin. (Yersinia enterocolitica, sometimes listed nearby in dictionaries, is a separate foodborne bacterium causing gut infection from undercooked pork — unrelated to yeasts.)