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Chlamydia Introduction

Chlamydia Introduction


Chlamydia is one of the most common sexually transmitted infections (STIs). You can get chlamydia from intercourse, anal sex or oral sex. Because chlamydia often doesn’t cause symptoms, many people who have chlamydia don’t know it and unknowingly infect other people. Regular screenings can help reduce chlamydia’s spread.

What is chlamydia?

Chlamydia is a common sexually transmitted infection (STI) caused by bacteria. Chlamydia infections are treatable and curable. However, its symptoms are often unnoticeable. It’s important to receive treatment for chlamydia as soon as possible. Left untreated, chlamydia can lead to serious complications and cause permanent damage to your reproductive organs.

How does chlamydia spread?

Once a person has chlamydia, they can spread it to their partners through sexual intercourse, anal sex or oral sex. Infections can also occur when a person with chlamydia shares sex toys with their partners.

Can you get chlamydia without having sex?

Yes. Sexual intercourse isn’t the only way you can get chlamydia. For example, sharing sex toys with a person who has the infection is another way you may get it.

Who does chlamydia affect?

Anyone who’s sexually active can get chlamydia. The bacteria that causes chlamydia transfers through vaginal fluid and semen. This means anyone who has sex can become infected with chlamydia and infect their partners, too. If you’re pregnant and have chlamydia, you can pass it on to your newborn.

How common is chlamydia?

Chlamydia is the most common STI caused by bacteria. About 1.5 million cases of chlamydia are reported each year. The number of infections is likely even higher. Most cases of chlamydia are asymptomatic, which means there are no signs or symptoms of an infection. Many of these cases likely go unreported.

Certain demographic characteristics (like age, gender and race) may make you more likely to get diagnosed with chlamydia. People who are more at risk for chlamydia include:

A teen or young adult aged 15 to 24. More than half of all diagnosed chlamydia cases in the U.S. occur in this age group. The rate is higher for women or people assigned female at birth (AFAB). For this reason, providers often recommend screening for chlamydia if you’re AFAB and between 15 and 24 years old.

A man who has sex with men (MSM). Chlamydia infections disproportionately affect men or people assigned male at birth (AMAB) who have sex with other men or partners AMAB, compared to those who have sex with women or people AFAB.

Black and non-Hispanic. Chlamydia infections disproportionately affect non-Hispanic Black populations.

Higher rates of transmission among certain groups are less about sexual behavior and more about networks and lack of access to STI prevention resources. For example, chlamydia is more likely to spread from person to person within communities that have higher infection rates. And it’s more likely to spread among groups that don’t have easy access to sex education or barriers to STIs like condoms and dental dams.

Chlamydia testing is recommended by the Centers for Disease Control and Prevention (CDC) as part of your regular health maintenance.

How do you get chlamydia?

Chlamydia infections spread through sexual contact, when vaginal fluid or semen containing the bacteria that causes chlamydia travels from one person to another. Sexual contact includes all kinds of sex, including sex that doesn’t involve penetration or ejaculation. There are lots of ways that the fluids from one person’s genitals can transmit the bacteria that causes chlamydia:

Intercourse. Bacteria pass from one person’s penis to their partner’s vagina or vice versa.

Anal sex. Bacteria pass from one person’s penis to their partner’s anus or vice versa.

Oral sex. Bacteria pass from one person’s mouth to their partner’s penis, vagina or anus, or vice versa.

Sex involving toys. Bacteria pass from a toy to a person’s mouth, penis, vagina or anus.

Manual stimulation of the genitals or anus. Less commonly, infected vaginal fluid or semen can come in contact with a person’s eye, causing an infection called conjunctivitis (pink eye). For example, this can happen if you touch the genitals of an infected person and then rub your eyes without washing your hands first.

How long can you have chlamydia without knowing?

Chlamydia is sometimes called a silent infection because the majority of people (between 50% and 70%) who have chlamydia — regardless of assigned sex — never notice symptoms.

People who do notice symptoms often don’t recognize the signs that they have chlamydia until a few weeks after they’ve been infected. Because chlamydia cases are often asymptomatic, it’s easy to spread chlamydia to someone else without realizing it. And it’s easy to miss out on receiving the treatment needed to prevent the serious complications that can result from chlamydia.

Most people don't know they have chlamydia because they don't symptoms. This means it spreads more easily.

Can you tell how long you've had chlamydia?

For most people, symptoms of chlamydia show up between one week and three months after unprotected sex. But, it can take longer than three months. Your healthcare provider may learn more about the infection when they diagnose it. For example, a provider may be able to tell that the infection has spread to your fallopian tubes or testicles. It’s important to receive regular testing for STIs if you’re sexually active because you may unknowingly have an infection.

What are the symptoms of chlamydia?

If you do notice symptoms, you’ll likely experience them differently based on if you have a penis or vagina.

Signs of chlamydia in women and people AFAB

Chlamydia bacteria often cause symptoms that are similar to cervicitis or a urinary tract infection (UTI). You may notice:

White, yellow or gray discharge from your vagina that may be smelly.

Pus in your urine (pyuria).

Increased need to pee.

Pain or a burning sensation when you pee (dysuria).

Bleeding in between periods.

Painful periods.

Painful intercourse (dyspareunia).

Itching or burning in and around your vagina.

Dull pain in the lower part of your abdomen.

Signs of chlamydia in men and people assigned male at birth (AMAB)

Chlamydia bacteria most often infect your urethra, causing symptoms that are similar to nongonococcal urethritis. You may notice:

Mucus-like or clear, watery discharge from your penis.

Pain or a burning sensation when you pee (dysuria).

Other signs of chlamydia

Chlamydia can affect parts of your body other than your reproductive organs, such as your:

Anus. You may notice pain, discomfort, bleeding or a mucus-like discharge from your buttocks.

Throat. You may have a sore throat, but you usually won’t notice symptoms if the bacteria’s in your throat.

Eyes. You may notice symptoms of conjunctivitis if C. trachomatis bacteria get in your eye. Symptoms include redness, pain and discharge.

See your healthcare provider immediately if you notice any of these symptoms.

What are the first symptoms of chlamydia?

Most people who have chlamydia never notice symptoms. But an unusual discharge from your vagina or penis may be a sign that you have a chlamydia infection. Pain, bleeding or discharge from your bottom can also be a sign of chlamydia.

How is chlamydia diagnosed?

The most common test for chlamydia is called a nucleic acid amplification test (NAAT). Your provider takes a sample of fluid by doing a vaginal/cervical swab or collecting a urine sample. Then, they send the sample off to a lab to check for the bacteria that causes chlamydia. Your provider may do the test in an office, or they may ask you to do an at-home chlamydia test. Follow your provider’s instructions carefully to ensure you get accurate test results.

Because most chlamydia cases are asymptomatic, it’s important to get screened for chlamydia even if you don’t notice any signs of infection. The CDC recommends that sexually active women or people AFAB who are high-risk for chlamydia get screened regularly. People with a vagina, more so than people with a penis, experience the most severe complications from chlamydia. For this reason, anyone with a vagina should be screened regularly, too.

You’re considered high-risk if you:

Are under 25.

Are pregnant.

Have a new partner.

Have multiple partners.

Have had chlamydia infections previously.

Men or people AMAB should get screened for chlamydia if:

You live in or visit a setting where chlamydia spreads frequently, like correctional facilities, adolescent clinics and sexual health clinics.

You have sex with other men or people AMAB.

Regardless of your age, reproductive anatomy, or other risk factors — you should discuss your sexual history and sexual activity with your healthcare provider. Your provider is your best resource for offering guidance on how often you should be tested for chlamydia and other STIs.

Can chlamydia just go away?

You should never wait for chlamydia to go away on its own. Left untreated, chlamydia can cause serious harm to your health. If you’re sexually active, you run the risk of infecting others, putting them at risk of experiencing severe complications, as well.

Can chlamydia be cured?

Yes. Chlamydia can be treated and cured. Some sexually transmitted bacterial infections are starting to become resistant to antibiotics, though, and this makes them harder to treat. With this in mind, the best way to fight chlamydia is to prevent infections from spreading.

What can happen if chlamydia isn’t treated?

Untreated chlamydia can put your health at risk. Make an appointment with your provider immediately if you notice any symptoms of chlamydia, and get regular STI screenings to avoid complications later.

Untreated chlamydia can cause:

Pelvic inflammatory disease (PID). PID is a serious condition that requires hospitalization. It can occur when an untreated STI, like chlamydia, damages your reproductive organs. PID can lead to infertility and chronic pelvic pain. PID can block the tubes and may lead an ectopic pregnancy, which is life-threatening for the fetus and potentially deadly for the mother or gestational parent, too.

Pregnancy complications. An untreated infection can lead to pre-term delivery. Also, if you’re pregnant and have chlamydia, you can pass the infection on to your newborn. Babies born with chlamydia may have pneumonia or conjunctivitis that could lead to blindness if not treated. If you’re pregnant, you should receive testing for chlamydia at your first prenatal appointment.

Infertility. An untreated infection can cause permanent damage to your fallopian tubes, uterus or vagina, making it hard to become pregnant.

Complications of chlamydia for men and people AMAB

Untreated chlamydia can cause:

Epididymitis. Infection can spread to the testicles and the tube that carries sperm to your testicles (epididymis), causing symptoms like pain, swelling and tenderness in your testicles.

Reduced fertility. Chlamydia can harm your sperm, negatively impacting your ability to conceive.

Complications of chlamydia that can affect everyone

Untreated chlamydia can spread to your bloodstream, which:

Increases your risk of getting reactive arthritis, which causes your joints to swell and feel painful.

Increases your chances of contracting HIV.