The cause(s) of vestibulodynia (VVS) is not known.  In some women, the problem may have started as a yeast infection, but although many women are told their problem is caused by a “chronic yeast infection” this is rarely the cause of vestibulodynia (VVS). Although we have not been able to prove what causes vestibulodynia (VVS), there are theories. In comparison to women without pain, women with vulvodynia may be genetically predisposed to having more inflammatory cells and fewer antiinflammatory cells in their skin. Not only do the inflammatory cells cause inflammation they also cause the growth of more inflammatory cells and more than the usual number of pain nerve fibers in the skin. This makes the skin more sensitive to pain. The extra pain nerve fibers in the skin means that women with vulvodynia feel pain pain to a stimulus that is painless to everyone else. Inability to break this self-perpetuating cycle of inflammation can lead to changes in the rest of the nervous system such that patients experience pain in other muscles far away from the original site of inflammation (for example in the arms). This may help to explain the association of vestibulodynia (VVS) with fibromyalgia. Another finding in women with vestibulodynia (VVS) is that they have spasm of the pelvic muscles. Most theories assume that the chronic inflammation of the skin causes the muscle spasm. Others think that it is an involuntary reflexive in anticipation of the ongoing pain with attempted intercourse. However in a few patients, the problem may start with spasm of the pelvic muscles and that is what causes the pain.