The clitoris is a sexual organ located at the front of the vulva, and its primary function is pleasure. What most people think of as “the clitoris” is actually just a small external tip. The full structure extends several inches inside the body, wrapping around the vaginal canal and urethra in a wishbone-like shape.
More Than What You Can See
The visible part, called the glans, averages about 6.4 millimeters long and 5.1 millimeters wide. It sits at the top of the vulva, tucked under a fold of skin called the clitoral hood. This tiny nub is what most people are referring to when they say “clitoris,” but it represents only a fraction of the whole organ.
Beneath the surface, the clitoris has a body that extends downward and splits into two legs called crura. These legs average over 5 centimeters long each, making them the largest part of the structure. They flare outward and run along either side of the vaginal canal. Flanking the vagina are two additional structures called vestibular bulbs, also about 5 centimeters long. Together, the glans, body, crura, and bulbs form an interconnected cluster of erectile tissue that partially surrounds both the urethra and the vagina.
MRI studies published in the early 2000s by Australian urologist Helen O’Connell were among the first to clearly map this internal anatomy in living women. Her imaging showed that the bulbs, body, and crura form a single erectile tissue cluster, challenging decades of anatomy textbooks that either minimized or omitted most of the organ’s internal structure.
How It Develops
Early in fetal development, every embryo has a structure called the genital tubercle. This tissue has the potential to become either a penis or a clitoris, depending on hormone exposure. Without the influence of androgens (hormones like testosterone), the genital tubercle develops into a clitoris. With androgens, it becomes a penis. This shared origin means the two organs have parallel structures: both contain erectile tissue surrounded by the same type of tough outer layer, and both have a glans at the tip. The key difference is that the urethra does not run through the clitoris.
Why It’s So Sensitive
The clitoris is densely packed with nerve fibers. The main sensory pathway runs through the dorsal nerve of the clitoris, a branch of the pudendal nerve that travels along the pelvic bone and enters the clitoral shaft from above. Histological counts have found roughly 3,100 nerve fibers (axons) in just one half of the clitoral body, about 71% of which are the myelinated type that transmit signals quickly. This concentration of nerve fibers in such a small area is what makes the glans one of the most sensitive spots on the human body.
What Happens During Arousal
The internal parts of the clitoris are made of erectile tissue, the same spongy, blood-vessel-rich material found in a penis. In its resting state, the smooth muscle in this tissue stays contracted, keeping blood flow minimal. During sexual stimulation, nerve signals trigger the release of a chemical messenger (nitric oxide) that relaxes the smooth muscle in the clitoral arteries. Blood rushes in, pressure builds inside the erectile chambers, and the tissue swells.
The glans pushes outward slightly and becomes more sensitive. The vestibular bulbs can double in size as they engorge with blood. This swelling of the entire internal structure is part of what creates sensation during both direct clitoral stimulation and vaginal penetration. Researchers describe the clitoris, urethra, and front vaginal wall as a functional complex, meaning stimulation of the vaginal wall can indirectly stimulate the surrounding clitoral tissue, contributing to orgasm.
Normal Size Variation
Clitoral size varies widely from person to person, and most of that variation is completely normal. In adults, the glans alone ranges from a few millimeters to close to a centimeter across. The total internal length, including the body and crura, can reach 9 to 11 centimeters. Factors like age, hormone levels, and genetics all influence size. The clitoris can also change over a lifetime: it may grow slightly during puberty and pregnancy, and tissue can thin somewhat after menopause as estrogen levels drop.
Conditions That Can Affect It
One of the more common issues is clitoral adhesions, where the hood partially or fully sticks to the glans. Dead skin cells and natural oils can build up in the closed space underneath, sometimes forming small cyst-like masses. This can cause a persistent irritation (often described as feeling like a grain of sand), pain, hypersensitivity, or difficulty with arousal. Contributing factors include skin conditions like lichen sclerosus, recurrent yeast or bacterial infections, low hormone levels (particularly around menopause or with certain hormonal contraceptives), and prior genital trauma. The exact cause often can’t be pinpointed in any individual case.
Because the glans is tucked under the hood, these adhesions can go unnoticed for years. They’re treatable, but they require a provider who specifically examines the glans during a pelvic exam, which is not always part of routine practice.