Can nuvaring cause a yeast infection? if so how do i treat it?

Vaginal yeast: Nuvaring won't cause yeast, but any vaginal manipulation could trigger it -- for example, if your ring was recently inserted. There are several effective over the counter vaginal meds for yeast. Look for active ingredient ending in "azole". All work well; choose based on cost and convenience. But get care first if any doubt about the diagnosis. For example, vaginal discharge usually isn't yeast.