Chlamydia

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What is chlamydia and how common is it?
How do you get chlamydia?
What are the symptoms of chlamydia?
How is chlamydia diagnosed?
Who should get tested for chlamydia?
What is the treatment for chlamydia?
What should I do if I have chlamydia?
What health problems can result from untreated chlamydia?
How can chlamydia be prevented?

What is chlamydia and how common is it?

Chlamydia (pronounced kluh-mid-ee-uh) is the most frequently reported sexually transmitted disease (STD) caused by bacteria (Chlamydia trachomatis) in the U.S. An estimated 2.8 million Americans get chlamydia each year. Women are often reinfected, meaning they get the STD again, if their sex partners are not treated. Reinfections place women at higher risk for serious reproductive health complications, including infertility.

How do you get chlamydia?

Sexually active women and men can get chlamydia through sexual contact with an infected person. Chlamydia can be passed during vaginal, anal, or oral sex. Because there are often no symptoms, people who are infected may unknowingly pass chlamydia to their sex partners.

An infected mother can also pass chlamydia to her baby during childbirth. Babies born to infected mothers can get pneumonia or infections in their eyes, also called conjunctivitis.

The more sex partners a person has, the greater the risk of getting infected with chlamydia. Chlamydia is easily confused with gonorrhea, another STD. Gonorrhea and chlamydia have similar symptoms and can have similar complications if not treated, but the two STDs have different treatments.

What are the symptoms of chlamydia?

Chlamydia is known as a "silent" disease because 75 percent of infected women and at least half of infected men have no symptoms. If symptoms do occur, they usually appear within 1 to 3 weeks of exposure. Symptoms, if any, might include an abnormal vaginal discharge or a burning sensation when urinating. The infection is often not diagnosed or treated until there are complications. If you think you have chlamydia or are concerned about it, both you and your sex partner should see a doctor right away.

The infection first attacks the cervix and urethra. Even if the infection spreads from the cervix to the uterus and fallopian tubes, some women may still have no signs or symptoms. If you do have symptoms, you might have lower abdominal pain, low back pain, nausea, fever, pain during sex, and bleeding between menstrual periods.

Men with symptoms might have a discharge from the penis and a burning sensation when urinating. Men might also have burning and itching around the opening of the penis or pain and swelling in the testicles, or both. The bacteria also can infect the throat from oral sexual contact with an infected partner.

How is chlamydia diagnosed?

Only a doctor or nurse can diagnose chlamydia. There are laboratory tests to diagnose chlamydia. Some tests involve getting a sample from an infected site (cervix or penis) to be tested for the bacteria. A urine test can also tell if you have the bacteria. A Pap test is not a test for chlamydia.

Who should get tested for chlamydia?

The following people should have a test for chlamydia:

All sexually active females 25 and under, once a year.
Women older than 25 should consider having a test for chlamydia if they:
Have new or multiple sex partners
Have sex with someone who has other sex partners
Do not use condoms during sexual activity within a relationship that is not mutually monogamous, meaning their sex partners have sex with other people

If you have unusual vaginal discharge, burning with urination, or other symptoms listed above, make sure to see your doctor.

What is the treatment for chlamydia?

Antibiotics are used to treat and cure chlamydia. A single dose of azithromycin or a week of doxycycline are the most commonly used treatments. All sex partners should also be treated to avoid reinfection. You should not have sex until you and your sex partner(s) have finished treatment. There are safe antibiotics to cure chlamydia during pregnancy.

What should I do if I have chlamydia?

Chlamydia is easily treated, but it’s important for you to seek testing and get treatment right away. By seeking testing and getting treated, you are taking good care of your reproductive health. If you have chlamydia:

Get it treated right away. Visit a clinic, doctor, or nurse. Research suggests that having an STD increases your risk for getting infected with HIV, the virus that causes AIDS.
Follow your doctor’s orders and finish all the medicine that you are given. Even if the symptoms go away, you still need to finish all of the medicine.
Avoid having any sexual activity while you are being treated for chlamydia.
Tell your sexual partners, so they can be treated too.
Get a follow-up test three to four months after treatment to make sure that the infection has been cured.
See your doctor again if your symptoms do not disappear within one to two weeks after finishing the medicine.
See your doctor again within 3 to 4 months for another chlamydia test, especially if your sex partner was not treated or if you have a new sex partner.

Doctors, local health departments, and STD and family planning clinics have information about STDs and can give you a test to find out if you have chlamydia. Don’t assume your doctor will automatically test you for chlamydia – you can take care of yourself, though, by asking about chlamydia and requesting a test.

CDC-INFO has free information and offers list of clinics and doctors who provide treatment for STDs. Call CDC-INFO at 1-800-CDC-INFO (232-4636), TTY: 1-888-232-6348. You can get information from the phone line without leaving your name

What health problems can result from untreated chlamydia?

If untreated, chlamydia infection can cause serious reproductive and other health problems. Like the disease itself, the damage that chlamydia causes is often "silent."

In women, the chlamydia bacteria often infect the cells of the cervix. If not treated, the infection can spread into the uterus, fallopian tubes, and ovaries and cause pelvic inflammatory disease (PID). This happens in up to 40 percent of women with untreated chlamydia. PID can cause:

Infertility. This is the inability to get pregnant. The infection scars the fallopian tubes, keeping eggs from being fertilized.
An ectopic or tubal pregnancy. This means that a fertilized egg starts developing in the fallopian tube instead of moving into the uterus. This is a dangerous condition that can be deadly to the woman.
Chronic pelvic pain. Pain that is ongoing, usually from scar tissue.

Untreated chlamydial infections can also cause inflammation of the bladder. Women who have chlamydia may also be more likely to get HIV, the virus that causes AIDS, from a person who is infected with HIV. In people having anal sex with a partner who has chlamydia, the bacteria can cause proctitis, which is an infection of the lining of the rectum. The bacteria causing chlamydia infections can also be found in the throats of people who have oral sex.

Untreated chlamydia in men typically causes infection of the urethra, the tube that carries urine from the body. Infection sometimes spreads to the tube that carries sperm from the testis. This may cause pain, fever, and even infertility.

In pregnant women, chlamydia infections may lead to premature delivery. Babies born to infected mothers can get infections in their eyes, called conjunctivitis or pinkeye, as well as pneumonia. Symptoms of conjunctivitis include discharge from the eyes and swollen eyelids, usually showing up within the first 10 days of life. Symptoms of pneumonia are a cough that steadily gets worse and congestion, usually showing up within three to six weeks of birth. Both of these health problems can be treated with antibiotics.

How can chlamydia be prevented?

There are things you can do to lower your risk for getting chlamydia:

Don’t have sex. The best way to prevent chlamydia or any STD is to practice abstinence, or not having vaginal, anal, or oral sex.
Be faithful. Have a sexual relationship with one partner who has been tested for chlamydia and is not infected is another way to reduce your chances of getting infected. Be faithful to each other, meaning that you only have sex with each other and no one else.
Use condoms. Condoms can lower the risk of passing chlamydia, so protect yourself with a condom EVERY time you have vaginal, anal, or oral sex. Condoms should be used for any type of sex with every partner. For vaginal sex, use a latex male condom or a female polyurethane condom. For anal sex, use a latex male condom. For oral sex, use a dental dam. A dental dam is a rubbery material that can be placed over the anus or the vagina before sexual contact.
Know that some methods of birth control, like birth control pills, shots, implants, or diaphragms, will not protect you from STDs. If you use one of these methods, be sure to also use a latex condom or dental dam (used for oral sex) correctly every time you have sex.
Talk with your sex partner(s) about STDs and using condoms. It’s up to you to make sure you are protected. Remember, it’s YOUR body! For more information, call the Centers for Disease Control and Prevention at (800) 232-4636.
Talk frankly with your doctor or nurse and your sex partner(s) about any STDs you or your partner have or had. Try not to be embarrassed. Being honest could save your lives.
Learn the symptoms of chlamydia. But remember that chlamydia often has no symptoms. Seek medical help right away if you think you may have chlamydia or another STD.

For More Information . . .

You can find out more about chlamydia by contacting the National Women's Health Information Center (800-994-9662) or the following organizations:

CDC Info, HHS
Phone: (800) CDC-INFO or (800) 232-4636

CDC National Prevention Information Network (NPIN), CDC, HHS
Phone: (800) 458-5231
Internet Address: http://www.cdcnpin.org

National Center for HIV, STD and TB Prevention, CDC, HHS
Internet Address: http://www.cdc.gov/std

National Institute of Allergy and Infectious Diseases
Phone: (301) 496-5717
Internet Address: http://www.niaid.nih.gov/publications/stds.htm

American Social Health Association
Phone Number(s): (800) 227-8922
Internet Address: http://www.ashastd.org

Planned Parenthood Federation of America
Phone Number(s) (800) 230-7526
Internet Address: http://www.plannedparenthood.org

This FAQ was developed from fact sheets of the National Institute of Allergy and Infectious Diseases and the Centers for Disease Control and Prevention.

All material contained in the FAQs is free of copyright restrictions, and may be copied, reproduced, or duplicated without permission of the Office on Women's Health in the Department of Health and Human Services; citation of the sources is appreciated.

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This FAQ was reviewed by the Division of STD Prevention, Centers for Disease Control and Prevention.

Content last updated May 1, 2005.