Conditions that disturb the normal environment in the vagina, or affect a woman's immune system will increase the likelihood of infections. While frequent yeast infections can be linked to diabetes, repeated courses of antibiotics, pregnancy, corticosteroid use, or HIV infection, most women have no risk factors. Yeast infections are usually easy to treat. Most infections are caused by the yeast Candida albicans and, thankfully, whether you use a three-day course of a vaginal cream or oral medications, or even single dose therapies, most yeast infections respond quickly. Most, but not all.
Some infections are severe and can require longer courses of treatment.
Infections can be harder to treat in women who have diabetes. Further, certain infections are caused by more resistant types of yeast, such as Candida glabrata . Again, while some women have risk factors, most do not. Recurrent infections are more likely to be due to the less common types of yeast, the non-albicans species. Further, while treating the women's sex partners is usually not necessary in simple infections, it can be a good idea when faced with recurrent infections.