So you’re about to have sex. Or you thought you were until you noticed a drought in your vagina. Occasional dryness is common, but that doesn’t make it any less annoying. While an autoimmune disorder called Sjogren’s syndrome can affect your moisture-producing glands, the most common cause of a dry vagina is low estrogen, which is most often associated with menopause.

But if you take birth control pills, antihistamines, or are frequently stressed, you might also find yourself reaching for some lube. “I see a lot of vaginal dryness in women of all different ages,” says Dr. Kathleen Green, an OBGYN who specializes in sexual wellness at the University of Florida Health Women’s Center. Whether you’re 20 or 50, knowing why your lubrication is lacking can be the key to getting your moisture back. Here are some reasons your vagina might be drier than you’d like and Dr. Green’s advice on what can help.

Lack of arousal
Many of her patients under 25 complain they aren’t having fun in the bedroom and wonder why they can’t orgasm from penetration alone. “Patients frequently see me because they don’t have an enjoyable sex life, they have painful sex,” says Dr. Green. “When I ask them about foreplay, they look at me blankly.”

Working up to sex is important because arousal increases blood flow to the genitals, which enlarges the clitoris —basically causing a vaginal erection. Then the Bartholin’s glands, two pea-sized ducts inside the vagina, release lubrication into the vaginal canal. Dr. Green explained that in a perfect world, people would get a heavy dose of clitoral stimulation and wait until they’re about to have an orgasm before they have sex.

Stress
Anxiety and stress can interfere with sexual arousal, which in turn prevents the vagina from self-lubricating. In an analogy that is helpful — but not so appealing — Dr. Green describes trying to have sex while you’re stressed like trying to have a bowel movement while you’re clinching. In terms of sex, being tense can increase tightness in the vagina and result in less lubrication.

“If your body can’t relax, the pelvic floor is not going to be able to relax, there’s not going to be increased blood flow,” says Dr. Green. “Those glands are not going to be able to release moisture.”

Allergy meds and cancer treatment
Several medications can lead to dryness, including decongestants in cold medicine and antihistamines used to treat allergies. Chemotherapy and anti-estrogen drugs used to treat breast cancer (and endometriosis) can also reduce estrogen levels, which thins out vaginal membranes and leads to less naturally-produced fluid for lubrication. A common side effect of antidepressants is difficulty getting aroused or having an orgasm, which can make self-lubrication more difficult.

Breastfeeding
Research shows those who are breastfeeding report more vaginal dryness three and six weeks postpartum than those who don’t, but this dryness can continue as long as someone keeps making milk. To be able to breastfeed, the body has to produce high levels of prolactin, which suppresses ovulation. This drastically lowers the amount of estrogen in the body, leading to a thinner, less-lubricated vagina.

“A breastfeeding woman’s vagina is almost the exact same as a postmenopausal vagina,” says Dr. Green.

What helps
If you experience occasional dryness, adding lubrication during sex is often all you need. Isn’t that what nightstands were really made for?  If the dryness causes itching or burning outside of sex, try a vaginal moisturizer. These ovules are inserted and absorbed by the vagina and can be used regularly to provide moisture that lasts for a few days.

Talk to your doctor if your symptoms are chronic or uncomfortable (or if it will make you feel better). If a provider doesn’t know how to properly address your concerns, ask for a referral to a physician who specializes in sexual wellness.

“There are a lot of great books and resources out there for women who aren’t happy with their sexual function,” says Dr. Green. “No woman should have to suffer through painful sex.”

Keri Wiginton is a writer and photographer focusing on issues related to women's health, mental well-being, and feminism. Her work has appeared in the Chicago Tribune, Washington Post, Austin-American Statesman, Tampa Bay Times and Houston Chronicle. Follow her work at www.keriwiginton.com or on Twitter at @keriphoto.