For more info where this came from: http://www.mayoclinic.com/health/painful-intercourse/DS01044

Causes of entry pain

Pain during penetration may be associated with a range of factors, including:

• Inadequate lubrication. This is often the result of not enough foreplay. Inadequate lubrication is also commonly caused by a drop in estrogen levels after menopause, after childbirth or during breast-feeding. In addition, certain medications are known to inhibit desire or arousal, which can decrease lubrication and make sex painful. These include antidepressants, high blood pressure medications, sedatives, antihistamines and certain birth control pills.
• Injury, trauma or irritation. This includes injury or irritation from an accident, pelvic surgery, female circumcision, episiotomy or a congenital abnormality.
• Inflammation, infection or skin disorder. An infection in your genital area or urinary tract can cause painful intercourse. Eczema or other skin problems in your genital area also can be the problem.
• Reactions to birth control products. It's possible to have an allergic reaction to foams, jellies or latex. Pain may also be caused by an improperly fitted diaphragm or cervical cap.
• Vaginusmus. Involuntary spasms of the muscles of the vaginal wall (vaginismus) can make attempts at penetration very painful.
• Vestibulitis. Painful penetration also occurs in a condition called vestibulitis, which is characterized by unexplained stinging or burning around the opening of your vagina.

Causes of deep pain

Deep pain usually occurs with deep penetration and may be more pronounced with certain positions. Causes include:

• Certain illnesses and conditions. The list includes endometriosis, pelvic inflammatory disease, uterine prolapse, retroverted uterus, uterine fibroids, cystitis, irritable bowel syndrome, hemorrhoids and ovarian cysts.
• Infections. An infection of your cervix, uterus or fallopian tubes can cause deep pain.
• Surgeries or medical treatments. Scarring from surgeries that involve your pelvic area, including hysterectomy, can sometimes cause painful intercourse. In addition, medical treatments for cancer, such as radiation and chemotherapy, can cause changes that make sex painful.

Emotional factors

Emotions are deeply intertwined with sexual activity and may play a role in any type of sexual pain. Emotional factors include:

• Psychological problems. If you experience anxiety, depression, concerns about your physical appearance, fear of intimacy or relationship problems, it can contribute to painful intercourse.
• Stress. Your pelvic floor muscles are very sensitive to stress. So stress can lead to painful intercourse.
• History of sexual abuse. Most women with dyspareunia don't have a history of sexual abuse, but if you have been abused, it may play a role.

Sometimes, it can be difficult to tell whether psychological factors are a cause or result of dyspareunia. Initial pain can lead to fear of recurring pain, making it difficult to relax, which can lead to more pain.