Two common conditions that afflict women are yeast infections and cystitis (often called urinary tract infections). Cystitis results from bacterial infections. There can be some other causes at times including: medications, radiation or chemotherapy. Yeast infections occur when there is too much accumulation of yeast in moist and warm spots of the body. Too much bacteria can result in yeast infections. Antibiotics being used to treat other infections can also result in yeast related infections.