What’s the Difference Between Chlamydia and Gonorrhea?

By Andrew Yocum, MD
Medically reviewed checkmarkMedically reviewed
March 2, 2022

Chlamydia and gonorrhea are the two most common bacterial sexually transmitted infections (STIs) in the United States. Between the two infections, more than 2 million cases were reported to the Centers for Disease Control and Prevention (CDC) in 2019.

When left untreated, both chlamydia and gonorrhea can lead to more serious, long-term health problems, which is why testing is essential—regardless of whether or not you’re experiencing symptoms. 

If you’re sexually active, getting tested for STIs can help keep you and your sexual partners healthy. In fact, for women and people with vaginas under the age of 25, and people with new or multiple sex partners, the CDC recommends STI screens at least once a year.

Even people in monogamous, long-term relationships should get tested at least once.

STI screening can help with early diagnosis and treatment. Diagnosing potential STIs early can reduce the risk of an STI leading to a more serious health complication.

Fortunately, there are antibiotics that can effectively treat both chlamydia and gonorrhea when diagnosed.

In this article, I’ll describe the differences between chlamydia and gonorrhea, including their causes and symptoms. I’ll talk about how each is treated and diagnosed, and which measures can help prevent them.

What is Chlamydia vs. Gonorrhea?

Chlamydia and gonorrhea are both common, highly contagious bacterial STIs. Both can be spread through unprotected sexual contact.

These infections are often found in the genitals, but they can also be found in the rectum and throat

But they are not the same infection, and they are not caused by the same bacteria. Gonorrhea is caused by the Neisseria gonorrhoeae bacterium, also known as gonococcus.

Chlamydia is caused by bacteria called Chlamydia trachomatis.

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What Are the Symptoms?

Not all people infected with chlamydia or gonorrhea experience symptoms.

This can delay the time to diagnosis, as people who have the infection often don’t know until a test confirms the diagnosis.

Chlamydia symptoms

When symptoms are present, they can be different in men and women.

Common symptoms of chlamydia in females or other people with vaginas are:

  • Redness and swelling of the vagina
  • Vaginal itching and burning
  • Change in vaginal discharge
  • Painful urination
  • Feeling the need to urinate frequently
  • Painful sexual intercourse

In males or other people with penises, symptoms of chlamydia include:

  • Burning sensation during urination
  • Unusual discharge from the penis
  • Abdominal pain (particularly in the lower abdomen)
  • Pain or swelling of the testicles 

Gonorrhea symptoms

Symptoms of gonorrhea also vary among men and women.

The most common symptoms of gonorrhea in females or other people with vaginas include:

  • Vaginal itching, burning, swelling, or redness
  • Increased or yellowish vaginal discharge
  • Painful or burning sensation when urinating
  • Urinating more frequently than usual
  • Bleeding between menstrual periods, or experiencing prolonged, heavier than usual menstrual periods
  • Painful intercourse
  • Abdominal or pelvic pain

In males and other people with penises, the most common symptoms of gonorrhea are:

  • Painful or burning sensation when urinating
  • White, yellow, or green discharge from the penis

What Causes Chlamydia and Gonorrhea?

Both infections are caused by bacteria. Gonorrhea is caused by Neisseria gonorrhoeae bacterium while Chlamydia is caused by Chlamydia trachomatis bacterium.

Any sexually active person can become infected with gonorrhea or chlamydia, but there are some factors that can increase the risk of contracting the infection.

These include:

  • Having unprotected sex with new or multiple partners
  • Having a sex partner with confirmed chlamydia, gonorrhea, or another STI
  • If you’re young and sexually active 
  • If you currently have another STI
  • If you’ve recently had another STI

Data from 2019 shows that Black Americans are more likely than white Americans to be diagnosed with chlamydia, and that chlamydia may be particularly prevalent in men who have sex with other men.

Treatment

Chlamydia and gonorrhea are bacterial infections that require treatment with antibiotics.

Neither infection can be effectively treated at home, which is why it’s crucial that you get tested to confirm the diagnosis and, if confirmed, consult with a healthcare provider about the right antibiotic treatment plan for you.

Once you’re diagnosed with chlamydia or gonorrhea, a healthcare provider will speak to you about your treatment options and care plan.

Because re-infection is common, your provider will likely recommend retesting after you finish the recommended treatment plan. Additionally, they may recommend testing for additional STIs, and will recommend abstaining from sex while you’re on antibiotics and for at least one week after finishing treatment.

The optimal treatment for gonorrhea is an antibacterial injection of ceftriaxone and, in some cases, a follow-up oral course of another antibiotic (usually azithromycin or doxycycline).

Chlamydia is generally treated with a single-dose of oral azithromycin or a prescription of oral doxycycline that is taken twice a day for one week. 

There are some strains of gonorrhea that have become resistant to common antibiotic treatments. Data shows that the prevalence of these strains is increasing in the US. On the other hand, there are few documented reports of antibiotic resistance in chlamydial infections.

Finally, it is vital to let all recent anal, oral, and vaginal sexual partners know about your diagnosis so that they can get tested and limit spread.

Diagnosis

The most common diagnostic test for both infections is nucleic acid amplification testing (NAAT) using a urine, cervical, or vaginal specimen.

When testing for chlamydia in females, vaginal swabs are the best way to ensure an adequate sample is collected.

Your provider can also test for gonorrhea and chlamydia by swabbing the throat, anus, or eyes. 

Complications

Unfortunately, both gonorrhea and chlamydia can lead to serious health conditions when left undiagnosed and untreated. That’s why it’s important to get tested often if you’re sexually active.

In both males & females

The following complications can occur: 

  • Disseminated gonococcal infection (DGI): An infection caused when gonorrhea spreads to the blood. It can lead to arthritis, tenosynovitis (inflammation of the lining of the sheath around a tendon), or dermatitis. DGI can be life-threatening.
  • Reactive arthritis: When symptomatic or asymptomatic chlamydia is left untreated, reactive arthritis can occur in both males and females.
  • Infertility: In some cases, complications of untreated gonorrhea and chlamydia can lead to infertility.

In males 

The following complications can occur in males and other people with penises:

  • Epididymitis: A condition characterized by the inflammation of the tube that holds the testicles in place in people with penises. Though rare, this condition can cause infertility.
  • Prostatitis: An infection of the prostate characterized by increased fluid in semen. Prostatitis can cause high fever, lower back pain, and painful ejaculations.

In females

The following complications can occur in females and other people with vaginas:

  • Pelvic inflammatory disease (PID): According to the CDC, symptomatic PID occurs in about 10-15% of women who don’t receive treatment for chlamydia. But PID can also occur as a complication of untreated gonorrhea. PID can cause severe abdominal and pelvic pain. Over time, it can lead to internal abscesses, damaged fallopian tubes, infertility, and an increased risk of miscarraige, premature birth, and ectopic pregnancy.

How to Prevent Chlamydia and Gonorrhea

Both infections are sexually transmitted, which means they can be spread through unprotected vaginal, oral, and anal sex.

Practicing abstinence can eliminate your risk of getting either disease, but practicing safe sex is often a more sustainable preventive measure.

To prevent the spread of these infections during sex, use latex condoms correctly. Condoms have other benefits too, including reducing the risk of other STIs and unplanned pregnancy.

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When to See a Doctor

If you’re sexually active and experiencing symptoms of chlamydia, gonorrhea, or another STI, speak with a provider as soon as possible.

These symptoms can include unusual discharge, burning sensations in the groin, and unexpected sores or rashes. If you’re sexually active and have not yet been tested for STIs, reach out to your provider to find out where you can get tested.

How K Health Can Help

Did you know you can get affordable primary care with the K Health app?

Download K to check your symptoms, explore conditions and treatments, and if needed text with a doctor in minutes. K Health’s AI-powered app is HIPAA compliant and based on 20 years of clinical data.

Frequently Asked Questions

Can chlamydia turn into gonorrhea?
No. Chlamydia and gonorrhea are different STIs caused by different bacteria. Though one infection cannot turn into another, people with one infection are more at risk for developing the other. For this reason, your provider may recommend testing for both infections at the same time, or testing for the other infection if the first is confirmed.
How common are chlamydia and gonorrhea?
Chlamydia and gonorrhea are the two most reported sexually transmitted infections in the United States. More than 2 million cases combined were reported to the Centers for Disease Control and Prevention (CDC) in 2019.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Andrew Yocum, MD

Dr Andrew Yocum is a board certified emergency physician. He graduated Summa Cum Laude from Kent State University with a Bachelor of Science in Molecular Biology before attending Northeast Ohio Medical University where he would earn his Medical Doctorate (MD).