Unlike penises, which are front and center, the clitoris is often shrouded in folds of skin and remains a bit of a mystery. Science—let alone sex ed—hasn't exactly gone out of its way to understand this amazing organ until fairly recently. In fact, research shows the clitoris was even omitted in an early version of the gold standard medical textbook Gray's Anatomy, and no scientist bothered to create a 3D image of what a stimulated clitoris looks like until French researchers finally did it a mere seven years ago, in 2009.
To clear up some common misconceptions and become more "clit literate," we enlisted the expertise of Leah Millheiser, M.D., director of the female sexual medicine program at Stanford University Medical Center. Here are seven things you probably don't know about one of your most pleasurable parts.
The clitoris is actually leagues ahead. The tiny organ has about 8,000 sensory nerve fibers, according to the Museum of Sex, which is nearly twice the amount found in the head of the penis. "The clitoral glans—the part we see—have more nerve endings than any other area on the human body," notes Millheiser. That's also why direct pressure on the clitoris often feels too intense, even painful in some cases, rather than pleasurable. "Women will say direct stimulation is very uncomfortable," she says. Instead, stimulating the hood of the clitoris (the skin covering it) may be better for arousal.
The clitoris may look like a small knob, but like an iceberg, there's much more going on beneath the surface. On average, it's 11 centimeters long so you can't see the majority of it, notes Millheiser. "The part you see is the clitoral glans, but there's another 10 centimeters that surrounds the vagina," she tells SELF. "It branches into 'legs'–it almost looks like a wishbone." In fact, a small study in the Journal of Sexual Medicine using ultrasound suggests that the G-spot is actually part of the clitoris.
"If women are noticing that their clitoris in its resting state is sticking out from under the clitoral hood or they've noticed a recent increase in the size in a non-aroused state, it might be a sign of a cyst or benign mass or a sign of too much testosterone," explains Millheiser. "That needs to be evaluated by your doctor."
Despite what you see in movies and porn, most women can't reach orgasm through vaginal penetration alone, according to the Mayo Clinic. Instead, many need to have their clitoris involved through direct or indirect stimulation to reach the big O. And that shouldn't come as a surprise considering that the clitoris has only one purpose: pleasure.
As women approach and go through menopause, it's common to have some vulvo-vaginal atrophy (whomp whomp) thanks to the drop in sex hormones estrogen and testosterone. "As a result, the clitoris gets smaller," notes Millheiser. Unfortunately, that makes it more challenging to climax and when you do, orgasms are often not as intense.
And where it's located matters. A 2014 study in the Journal of Sexual Medicine found that if the clitoris is located too far away from the vaginal opening, the more likely a woman is to have difficulty reaching orgasm. In the study, the researchers found that women whose clitoris was an average of 5 to 6 millimeters away from the vaginal opening reported rarely or never reaching orgasm.
When you're turned on, blood rushes to the clitoris, causing it to swell. "About 30 to 15 seconds before a woman has an orgasm, called the plateau phase, the clitoris gets pulled up into the clitoral hood," says Millheiser. At the same time, the top part of the vagina also swells—it actually gets bigger. "There's a ballooning effect of the upper one-third of the vagina," she explains, "likely to give more space for a penis and possibly ejaculation."
