How Gonorrhea Is Diagnosed

A gonorrhea diagnosis is based on lab analysis of a urine sample or a swab of the potentially infected area (vagina, urethra, or throat, for example). If you’re unable to see a physician, or you prefer to handle this privately, there are also kits you can use to self-test from home. 

If you suspect that you have been infected with Neisseria gonorrhoeae, the bacterium that causes gonorrhea, it’s important that you see a healthcare provider. This sexually transmitted infection (STI) often doesn’t cause symptoms, so you should be tested even if you feel well.

Labs and Tests

There are three tests used to diagnose gonorrhea:

• Bacterial culture, which looks for growth of N. gonorrhoeae
• Gram stain, in which N. gonorrhoeae is seen under a microscope with the aid of special dyes
• Nucleic acid amplification test (NAAT), which can provide genetic evidence of infection

Each has benefits and limitations.

Bacterial Culture

A bacterial culture can be highly effective in diagnosing gonorrhea of the genitals, rectum, eyes, or throat.

Cells collected with a swab of the affected area are sent to a lab, where they are added to a substance designed to promote the growth of N. gonorrhoeae.

Generally speaking, it can take from five to seven days to receive the results of a bacterial culture. If there is growth, the test is positive. If there is no growth, the test is negative.

A culture can also be used to determine whether a bacterium is resistant to any of the antibiotic drugs that are used to treat this infection. This is especially important if treatment doesn’t clear an infection or if disseminated gonococcal infection (DGI) develops.

DGI is a severe complication in which N. gonorrhoeae spreads through the bloodstream to organs in the body.

While culture results can provide definitive proof of an infection, the test can be marred if the swab is not taken properly. A bacterial culture is temperature-sensitive and it may be less accurate if there are any mistakes in the handling, storage, incubation, or processing of a sample.

Gram Staining

Gram staining is often used for diagnosing a gonorrheal infection in males.

It is typically performed by obtaining a swab from the urethra (the tube that allows pee to flow from the bladder outside of the body), as well as a first-catch urine sample. First catch is a method by which urination is withheld for at least an hour before collection and only the first 20 to 30 milliliters of urine are collected.

Special dyes are then added to the samples to tint the walls of bacteria, if present, so that they can be differentiated and identified with a microscope.

You should expect to receive your gram stain test results in two to three days. If the bacterium is present, you will get a positive result. If it is not, your lab report may say “negative” or “no organism seen.”

A gram stain test has a low sensitivity. That means that it is prone to false negatives, or results that indicate gonorrhea is not present when it really is.

As such, a negative result cannot be considered definitive. Other forms of testing would be necessary.

Nucleic Amplification Test (NAAT)

The NAAT identifies the genes unique to N. gonorrhoeae.

A urine sample or a swab of the vagina, cervix, or urethra is sent to a lab and processed using a technique that can make roughly a billion copies of the genetic material of bacteria, if present. This allows even small amounts of the bacteria to be detected, making it highly accurate.

NAAT results can be delivered within a few hours. You can expect to receive your lab report within two to three days.

Due to its speed and accuracy, the Centers for Disease Control and Prevention (CDC) recommends that the NAAT be used to diagnose gonorrheal infections of the rectum and throat.

Differential Diagnoses

Several medical conditions can cause symptoms similar to the symptoms of gonorrhea.

Common conditions your healthcare provider may consider during your diagnostic evaluation:

• Urinary tract infections (UTIs)
• Herpes simplex urethritis
• Vaginitis
• Bacterial vaginosis (BV)
  
• Epididymitis
• Mucopurulent cervicitis
• Bacterial conjunctivitis
• Orchitis

Our Doctor Discussion Guide below can help you start a conversation with your healthcare provider about what different results may mean.

Gonorrhea Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

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At-Home Testing

If you think you may have been exposed to gonorrhea, you might look for signs and symptoms before seeking out a test.

Stigma, embarrassment, and fear of disclosure are among the reasons some people say they avoid getting tested for sexually transmitted diseases (STDs). But you may also feel like a test just isn’t necessary if you feel fine.

Remember that being infected and not having symptoms is common.

To this end, an increasing number of public health advocates have endorsed the use of at-home STD tests, which provide consumers the autonomy and confidentiality they desire.

The most widely marketed home kits for gonorrhea require you to collect the swab and/or urine samples at home and mail them to the lab for analysis. You then log onto a secure website to get your results in three to five business days.

Drawback of At-Home Tests

Despite the appeal of at-home testing, there are many drawbacks.

Collecting samples tends to be more difficult than manufacturers suggest, and user error is rife.

Moreover, the cost of the kits can be prohibitive. Without insurance, the cost ranges from $40 to several hundred dollars.

If You Test Positive

If you receive a positive result for gonorrhea, you should have a comprehensive STD screening, including for chlamydia, syphilis, trichomoniasis, and HIV.

Contracting more than one of these STDs at the same time, known as co-infection, is common. Some co-infections, like HIV, are more likely to progress if you also have another STD.

If you used an at-home test, you should get this additional screening through a physician.

It is highly suggested that you contact current and recent sex partners and that they get tested (and treated, if needed). While the CDC recommends that you or your provider notify all partners you had sex within the 90 days prior to any symptoms starting or the confirmation of your diagnosis, you may want to go further back than that.

Once treatment is completed, a follow-up test is not required to confirm the infection has cleared as long as the recommended antibiotics are used.

However, given the high rates of reinfection, your healthcare provider may request that you be retested in three months irrespective of whether your partner(s) have been treated or not.

Screening Recommendations

Gonorrhea is the second most common STD in the United States, accounting for over 700,000 infections in 2021.

While testing for gonorrhea when an infection is suspected is important, screening for the infection—testing whether you believe you could have it or not—is important for some people.

The U.S. Preventive Services Task Force (USPSTF) recommends that screening for gonorrhea and other common STDs be performed in people who are at an increased risk of exposure and/or disease complications.

• Gonorrhea and chlamydia should be screened in those born female, including pregnant persons, under age 25, and at age 25 and up if they are at increased risk for infection.
• Syphilis should be screened in people at increased risk and in all pregnant persons.
• Hepatitis B should be screened in people at increased risk and in all pregnant persons.
• HIV screening should be conducted as part of a routine healthcare provider’s visit for all people ages 15 to 65 and for younger and older people at increased risk. HIV should also be screened in all pregnant persons.

If you are infected, you will continue to be contagious until you receive treatment, and there’s a risk of bringing the infection into a new relationship without even knowing.

Your partner’s sexual history and behaviors can affect your risk of STDs as well.

See your healthcare provider for screening. Or, to find a testing site near you, visit the CDC’s online testing site locator. Many of the listed clinics offer low-cost or no-cost confidential testing for qualified residents.