Cervix

Your cervix is a muscular, tunnel-like organ that connects your uterus and vagina. It’s an important part of the female reproductive system.

Your cervix allows fluids to pass between your uterus and vagina. It’s also a powerful gatekeeper. It can open and close in ways that make pregnancy and vaginal delivery possible.

A gynecologist can help make sure your cervix is healthy. Regular Pap smears allow your provider to check for issues that may be signs of disease.

What is the purpose of the cervix?

Your cervix plays important roles in the following:

• Menstruation: Your cervix opens slightly to allow period blood to flow out.
• Protecting your uterus: Your cervix helps prevent bacteria and viruses (and things like tampons) from getting inside your uterus.
• Sexual response: Some women experience pleasure when their cervix is touched during sex. For others, this can cause discomfort or pain.
• Fertility: Around ovulation, your cervix releases mucus that’s thinner and less acidic than usual. This makes it easier for sperm to get to your uterus.
• Conception: Sperm must travel through your cervix to reach your uterus. They then swim through your fallopian tubes to fertilize an egg.
• Pregnancy: During pregnancy, your cervix stays closed to keep the fetus in your uterus. It also makes a mucus plug that seals the entry to your uterus. Once it’s time for delivery, the mucus plug dissolves.
• Labor and delivery: During labor, your cervix becomes softer and thinner (effaces). It widens (dilates) so your baby can exit your uterus.

Where is the cervix located?

Your cervix is anywhere from 3 to 6 inches deep inside your vaginal canal. It begins at the base of your uterus. It extends downward onto the top part of your vagina.

Can you touch your cervix?

Yes, depending on the timing of your menstrual cycle. When inserting your longest finger into your vaginal canal, you should eventually reach a barrier that prevents your finger from going further. This barrier is your cervix. It may feel firm and tight, or soft and spongy.

The location and texture of your cervix change depending on whether you’re ovulating. It’s the softest and most difficult to reach during ovulation.

Be sure to wash your hands thoroughly with mild soap and warm water before touching your cervix. Otherwise, you could expose your cervix to bacteria and cause an infection.

What does it look like?

Your cervix is shaped roughly like a cylinder or tube. It’s wider in the middle and narrows at both ends, where it opens into your uterus (top) and vagina (bottom).

During a pelvic exam, your gynecologist can see the part of your cervix that’s at the top of your vaginal canal. It looks like a firm, rounded structure. It has a small, slit-like opening in the center. It’s usually pinkish in color. But it may look red or discolored if there’s an issue.

How long is the cervix?

The cervix is usually about an inch long. Cervical sizes vary, though. It depends on your age and whether you’ve given birth.

During pregnancy, the length of your cervix changes. It’s normally longer in the first and second trimesters. It shortens in the third trimester as you get closer to delivery.

What are the parts of the cervix?

Your cervix consists of the following parts:

• Internal OS: The opening that leads to your uterus. Your provider may mention it during pregnancy.
• Endocervical canal: A tunnel that extends from your internal OS to your ectocervix.
• Ectocervix: The part of your cervix that bulges onto the top of your vagina.
• External OS: The opening that leads to your vagina.

What is it made of?

Your cervix is made of strong fibromuscular tissue. Two main types of cells line your cervix:

• Glandular cells: These cells line the endocervical canal, the innermost part of your cervix.
• Squamous cells: These cells cover the ectocervix, the outermost part of your cervix.

These different cell types meet at an area called the transformation zone (TZ). This is where cell changes often happen. Your provider especially looks at the TZ during screenings for cervical cancer.

What are the common conditions that affect the cervix?

The most concerning cervical conditions involve the human papillomavirus, or HPV. HPV is a sexually transmitted infection (STI) that sometimes leads to cervical cancer.

Conditions that affect your cervix include:

• Cervical dysplasia: Abnormal cell growth, most often resulting from an HPV infection (sometimes, but not always, leads to cervical cancer)
• Cervical cancer: Cancerous cell growths on your cervix
• Cervicitis: Inflammation of your cervix caused by an STI or skin irritation (reactions to contraceptives can also cause this)
• Cervical polyps, fibroids and cysts: Fleshy or fluid-filled growths on your cervix
• Cervical ectropion: Glandular cells on the inner portion of your cervix become visible from the outside (a harmless condition)

Pregnancy conditions involving your cervix include:

• Cervical insufficiency: This is when your cervix shortens or opens too early. It can lead to miscarriage and preterm birth.
• Placenta previa: The placenta completely or partially covers your cervix. These pregnancies usually require C-sections.
• Cervical pregnancy: This is a rare complication in which an egg implants in the endocervical canal instead of your uterine lining.

What are common symptoms that something is wrong?

Many conditions affecting your cervix don’t cause symptoms. You may not know that something is wrong. For example, cervical dysplasia and early-stage cervical cancer often don’t have noticeable signs.

This is why it’s so important to get regular Pap smears. They check for any irregular cell growth. Only a healthcare provider can tell you if your cervix is normal and healthy.

If you do notice signs, they may include:

• Abnormal vaginal bleeding, including heavy menstrual bleeding or bleeding between periods
• Vaginal discharge that may be watery or bloody, odorless or smelly
• Feeling tired, uncomfortable, or generally unwell
• Pain when you pee

How can I keep my cervix healthy?

To keep your cervix healthy, you can:

• Talk to your provider about the HPV vaccine. The U.S. Food and Drug Administration (FDA) has approved three vaccines that prevent the types of HPV that lead to cervical cancer: Gardasil®, Gardasil 9® and Cervarix®. Getting the vaccine greatly reduces your risk of cervical cancer.
• Get screened for HPV and cervical cancer regularly. Talk to your provider about how often you should get screenings based on your age and unique health situation.
• Practice safer sex. Use condoms or dental dams any time you have intercourse, anal sex or oral sex. Avoid sharing sex toys, and limit your number of sexual partners.
• Avoid tobacco products. Research shows that HPV is more likely to progress to cancer if you smoke or use tobacco products.