Your cervix is the lower third of your uterus, a narrow passage that connects your uterus to your vagina. It’s a small but essential structure that plays a role in menstruation, fertility, pregnancy, and childbirth. If you’ve ever wondered what your doctor is checking during a pelvic exam or what “dilation” means during labor, the cervix is at the center of it all.
Where the Cervix Is and What It Looks Like
The cervix sits at the very bottom of the uterus, forming a bridge between the uterine cavity above and the vaginal canal below. It has two openings: the internal os at the top (where the cervix meets the body of the uterus) and the external os at the bottom (where the cervix opens into the vagina). A narrow channel runs between these two openings.
The cervix has two distinct zones. The upper two-thirds, called the endocervix, is lined with glandular tissue that produces mucus. The lower third, called the ectocervix, is covered in tougher tissue similar to the lining of your vagina. The boundary where these two types of tissue meet is the area doctors pay close attention to during screening, because it’s where abnormal cell changes are most likely to develop.
What Your Cervix Does
The cervix acts as a gatekeeper between your vagina and your uterus. A small hole in the center allows menstrual blood to flow out and sperm to travel in. It’s also the reason a tampon or menstrual cup can’t get “lost” inside your body: the cervix blocks the way, with an opening too small for anything other than fluid to pass through under normal circumstances.
The mucus your cervix produces changes throughout your cycle to either help or hinder conception. Around ovulation, cervical mucus becomes thin and slippery, making it easier for sperm to swim through. At other times, the mucus is thicker and forms a more effective barrier. During pregnancy, this mucus thickens into what’s known as a mucus plug, sealing the cervical canal to help protect the developing baby from infection.
How It Changes During Your Menstrual Cycle
Your cervix isn’t static. Its position, firmness, and openness shift throughout each menstrual cycle in response to hormone levels.
- Follicular phase (after your period, before ovulation): The cervix sits at a medium height, feels firm, and is completely closed. Estrogen levels are still low at this point.
- Ovulation: Rising estrogen softens the cervix, pulls it higher in the vaginal canal, and causes it to open slightly. This is the most fertile window.
- Luteal phase (after ovulation): The cervix drops back to a medium position and closes, but stays soft due to progesterone.
- Menstruation: The cervix drops to its lowest point, feels firm, and opens partially to allow menstrual blood to pass through.
Some people track these changes as a fertility awareness method. The pattern of soft, high, and open during ovulation versus firm, low, and closed at other times can help identify your most fertile days.
How to Feel Your Own Cervix
You can locate your cervix with a simple self-exam. Start at a time when it’s likely to be low and easy to reach, such as just before or after your period. Wash your hands thoroughly, including under your fingernails. Squat down, or prop one leg up on the toilet seat or edge of a bathtub. With your palm facing up, gently slide your longest finger into your vagina. Using lubricant can make this more comfortable.
Feel toward the top of the front vaginal wall, closer to your belly button than your back. You’re looking for a round, raised circle with a small dimple in the center. Around ovulation, it feels soft, like an earlobe. At other times in your cycle, it feels firmer, more like the tip of your nose. How deep you need to reach will vary depending on where you are in your cycle and your individual anatomy.
The Cervix During Pregnancy and Labor
During pregnancy, the cervix stays tightly closed and sealed with the mucus plug to protect the uterus. As your body prepares for delivery, two things happen: effacement and dilation.
Effacement is the process of the cervix softening, thinning, and shortening. Providers measure it in percentages. At 0% effaced, the cervix is still long and firm. At 100%, it has thinned out completely. Dilation is how wide the cervical opening stretches, measured in centimeters. The pushing stage of labor can’t begin until the cervix reaches 100% effacement and 10 centimeters of dilation. Losing the mucus plug is one of the early signs that effacement is underway.
In some pregnancies, the cervix opens too early, a condition called cervical insufficiency. Signs can include light vaginal bleeding, a feeling of pelvic pressure, or mild cramping. This is something providers monitor in people with a history of preterm birth or cervical procedures.
Common Cervical Conditions
Several benign conditions can affect the cervix. Cervicitis is inflammation of the cervix, usually caused by an infection but sometimes triggered by irritation from products like spermicides or latex. Symptoms can include unusual vaginal discharge, pain during sex or a pelvic exam, and bleeding between periods.
Cervical polyps and cysts are fleshy or fluid-filled growths that develop on the cervix. They’re most common during the reproductive years, particularly after age 20, and are almost always noncancerous. Many cause no symptoms at all and are found incidentally during a routine exam. When they do cause problems, abnormal bleeding (especially between periods or after sex) is the most typical sign.
Cervical Cancer Screening
The cervix is one of the few places in the body where cancer can be reliably caught early through routine screening. Testing looks for high-risk strains of HPV (human papillomavirus), the virus responsible for nearly all cervical cancers, or for abnormal cell changes that could eventually become cancerous if left untreated.
For people aged 21 to 29, screening guidelines haven’t changed in recent years. Starting at age 30, the preferred approach is HPV testing every five years. A 2026 update from the American College of Obstetricians and Gynecologists now also gives people aged 30 to 65 the option of collecting their own samples for HPV screening every three years, rather than requiring a clinician-collected sample. Screening typically stops after age 65 for people with a history of normal results.