Painful intercourse, known medically as dyspareunia, is discomfort or pain that accompanies sexual intercourse. Depending on the cause, the pain may be mild or acute; in some cases, it makes sexual intercourse impossible. For most women, the first experience with sex is uncomfortable, usually due to the tearing of the hymen, perhaps coupled with insufficient vaginallubrication. After a period of adjustment, according to Dr. Helen Singer Kaplan, director of the Human Sexuality Program at New York Hospital Cornell University Medical Center, it is abnormal for intercourse to hurt. Dr. Kaplan has found that in about half of her patients who experience painful intercourse, the cause is physical; for the rest, emotional factors or both physical and psychological problems are responsible. Physical causes of persistent pain during intercourse include genital herpes, vaginitis, pelvic inflammatory disease, endometriosis, a displaced or tipped uterus, thinning of the vaginal tissues following menopause or during breast-feeding, and an allergic response to contraceptives. The problem can also be the result of a poorly sewn episiotomy or scarring from a childbirth injury. Among the causative emotional factors are anger, fear of pregnancy, and guilt. Childhood sexual abuse or a punitive upbringing in regard to sexual matters may be involved. Also, women who have been raped sometimes develop dyspareunia. When troubled feelings have been deeply repressed, they may lead to vaginismus; these are involuntary contractions or spasms of the vaginal muscles that make penetration impossible.