The phrase "yeast problem" refers to an issue caused by an overgrowth of yeast in the body. This can lead to health problems such as yeast infections or digestive issues. Full definition
Plus a host of yeast problems and gut issues related to all the natural flora being destroyed in the gut from even one dose of antibiotic. (greensmoothiegirl.com)
For example, too much sugar and / or simple carbohydrates can cause yeast problems. (natural-parenting-advice.com)
One had a severe yeast problem due to a grain allergy. (1800petmeds.com)