Can a vaginal yeast infection cause pelvic inflammatory disease?

No, but be careful: Yeast doesn't cause PID. However, the symptoms of yeast infection and STDs that can lead to PID often are similar. Therefore, it is very possible for a woman who thinks she has a yeast infection to get PID. If you suspect a yeast infection or have any symptoms like vaginal discharge, irritation, or odor -- and certainly if you have PID symptoms like pelvic pain -- see a doctor ASAP. Good luck!