When I talk to my friends about sex (which, as a relatively liberal 19-year-old girl, I do a lot) I am often surprised by how often they say they encounter some kind of discomfort or pain. One of my friends said that vaginal sex hurt every single time with her first boyfriend. To me, this seems to be not only a serious problem, but one that many women are suffering in relative silence.  It is also a common problem: according to WebMD, three out of four women say that they have felt pain during sex.

So, what is the cause? A quick Google search brings up hundreds of answers and pieces of advice for women seeking relief from mild to severe pain. The truth is there are many kinds of sexual pain, and even more potential causes. The most severe affliction seems to be vulvodynia, which is essentially chronic pain in the vulva (the area just outside of the vagina, including the opening and the surrounding labias.) According to the American Congress of Obstetricians and Gynecologists, one in five women may feel this kind of pain at one time. Doctors are still unsure of the cause of vulvodynia, but say that it can be triggered by emotionally or physically traumatic experiences like childbirth or scarring. Women who think they might have this condition should see a doctor immediately and consider physical therapy. They should also consider switching to cotton underwear and, if they douche, they should stop. Actually, scratch that. Just don’t douche no matter what.

Another frequent cause of pain is vaginal dryness, which can be triggered by several circumstances, most notably lack of arousal. The most obvious (and most fun!) solution to this problem is foreplay. Girls, don’t be afraid to ask for what you want. If what really gets you going is oral, ask for it. Very few guys will be unwilling to do something that you tell them gets you wet—and if they don’t want to get you excited, it’s time to have a talk about more than just your happy spot.

Unfortunately, no matter how quickly your partner can wiggle his tongue, sometimes the desert stays dry. Despite Seth’s conclusion in Superbad that teenage girls are “good to go” all the time, (quick note to males: don’t get your sex advice from any Judd Apatow movie) hormonal fluctuations can make a big difference in how naturally lubricated the vagina is. Basically, nature has rigged it so that a woman is most ready for sex (most turned-on, most lubricated) when she is ovulating and therefore most likely to become pregnant. Birth control pills can also have an effect on natural lubrication, as they change hormone levels to prevent ovulation (therefore disrupting nature’s cycles.) Women who suffer from consistent vaginal dryness despite being otherwise aroused should consider switching to pills with lower hormone levels. Additionally, all sexually active people should own a bottle of lube, preferably water-based or silicone-based versions that won’t degrade condoms. Using a little bit of lube to start off sexual activity can help a woman become naturally lubricated, by decreasing the sometimes-uncomfortable friction of fingering and penetration, thereby making the acts more pleasurable and therefore more arousing.

Surprisingly common and hush-hush is the issue of large penises. Despite the supposed female preference for male genitalia the size of a battering ram, those proud few endowed with large members may be doing more harm than good. The average size of the erect penis is about five or six inches, though size can vary drastically. However, the average length of the vagina, when aroused and fully elongated (yes, it changes size too!) is about five or six inches with almost no variation in size. This means that, even when fully aroused, a woman’s vagina just can’t hold the entire length of a larger penis. It also means that the man, especially during deep thrusting, may hit the woman’s cervix, or the opening to the uterus. Though the penis will not penetrate the cervix, this can be painful for women. In this situation the best option is a change in position. Consider positions that allow for tighter but shallower penetration, like spooning or missionary with the woman’s legs slightly closed. Also consider woman-on-top positions that allow the girl to control the amount of penetration.

Remember that most positions are workable if the man is able to show some restraint and avoid deep penetration. Talking to your partner is imperative. And girls, if the idea of talking about your pain freaks you out, just think about how long your guy would stay silent if he was wincing with every movement.

Francis is a member of the class of 2014 and The Argus sex columnist