Possible cause: Vaginismus. If penetration has gone from painful to downright impossible because your vagina is shut tight, it may signal a little-known condition called vaginismus, says Raquel Dardik, MD, associate professor of obstetrics and gynecology at NYU Langone Medical Center. Characterized by painful, involuntary contraction of the vaginal muscles, the cause is a mystery, though it may be the result of past trauma, like sexual abuse. “It's like your vagina has put up a 'do not enter' sign,” adds Dweck.
Get back in the sack: Ask your doctor specifically about vaginismus—otherwise, she might just blow it off as anxiety or stress. That would be a shame, because vaginismus is real, and it's definitely treatable. “We teach women exercises that help them relax the pelvic floor muscles, which can help a great deal,” says Dr. Dardik.