To get to the bottom of this rumor that stress can cause yeast infections, mbg spoke with a couple of functional medicine doctors and OB/GYNs. Here’s what they have to say about the possible connection. In other words, it might not be causing the infection, but stress could be the reason it’s sticking around for so long. Other possible causes of yeast infections are antibiotics, increased sugar intake, an imbalanced gut microbiome, Trubow says. According to the Centers for Disease Control (CDC), women who are pregnant, using hormonal contraceptives, or have a weakened immune system may also be more susceptible to vaginal candidiasis 1(a type of yeast infection).