Endometriosis 

Endometriosis is a condition in which the lining of the uterus – the endometrium – grows outside of the uterus. It often affects other structures in the pelvic region. Unfortunately, these growths can cause intense pain during intercourse. 

According to Everyday Health, more than half the women afflicted with endometriosis experience significant discomfort. Talk to your doctor about possible medical treatments, which may include hormone therapy to reduce the growths, and in some cases, surgery. 

Vaginusmus 

Another cause of pain during sex is vaginusmus, an odd-sounding medical term that simply means involuntary spasms or contractions of the vaginal muscles. Women frequently describe the sensation as burning, tearing or having “hit a wall,” explains The Society of Obstetricians and Gynecologists of Canada. The tightening itself doesn’t hurt; it’s only with penetration when pain occurs.