Gonorrhea and chlamydia are both bacterial STIs that infect the genitals, rectum, and throat, and their symptoms overlap so heavily that you can't reliably tell them apart by feel. They differ in the bacteria, the discharge, and the drug that cures each. Because they so often travel together, clinicians frequently test for both and may treat both at once.
~1.65M US cases/yr; cured with doxycycline
~601k/yr; ceftriaxone shot; resistance rising
| Item | Value |
|---|---|
| Chlamydia | curable — ~1.65M US cases/yr; cured with doxycycline |
| Gonorrhea | curable — ~601k/yr; ceftriaxone shot; resistance rising |
What each one is
Chlamydia
Chlamydia is caused by the bacterium Chlamydia trachomatis; most US genital infections come from the serovars labeled D through K CDC. It's the most-reported STI in the country — roughly 1.65 million cases in 2023, or about 492 per 100,000 people, a figure that has stayed roughly flat across 2020–2023 CDC AtlasPlus, 2023. It often produces no symptoms at all, which lets it spread and linger before anyone knows it's there.
Gonorrhea
Gonorrhea is caused by a different bacterium, Neisseria gonorrhoeae, and it can infect the genitals, rectum, and throat CDC. Unlike chlamydia, reported gonorrhea has been falling — about 601,000 cases in 2023 (180 per 100,000), down from a 2021 peak of 214 per 100,000. Gonorrhea tends to announce itself more loudly in men but is just as silent as chlamydia in many women.
Symptoms compared
Both infections share the same core complaints: burning when you pee, abnormal discharge, and bleeding between periods. You can't sort one from the other on symptoms alone. The differences are matters of degree.
Chlamydia is the more silent of the two. Roughly three quarters of infected women and half of infected men have no symptoms at all. When women do notice something, it's usually abnormal vaginal discharge or burning on urination. If the infection climbs into the upper reproductive tract, it can cause lower-abdominal or low-back pain, fever, pain during intercourse, and bleeding between periods — signs the infection is doing damage.
Gonorrhea tends to be more obvious in men: burning on urination and a white, yellow, or green penile discharge, and less commonly swollen or painful testicles. In women, gonorrhea is mostly silent too; when symptoms appear they're painful or burning urination, increased vaginal discharge, and bleeding between periods, nearly indistinguishable from chlamydia.
How to tell them apart
You usually can't, not from the outside. The symptoms overlap enough that a lab test is what settles it. A few features lean one way or the other:
- Discharge color and thickness can hint. A thick, frankly yellow-green penile discharge points more toward gonorrhea, while chlamydial discharge tends to be thinner or absent. This is only a tendency, and plenty of cases break it.
- Timing and loudness: gonorrhea symptoms in men often come on faster and more noticeably, whereas chlamydia is more likely to cause no symptoms at all in either sex.
- Co-infection muddies everything. Because the two so often occur together, the discharge you're looking at may be driven by both bacteria at once, which is one reason guessing fails.
Gonorrhea vs chlamydia at a glance
| Chlamydia | Gonorrhea | |
|---|---|---|
| Cause | Chlamydia trachomatis | Neisseria gonorrhoeae |
| Reported US cases (2023) | ~1.65 million | ~601,000 |
| Trend | Roughly flat | Falling from a 2021 peak |
| Symptoms in women | Mostly none; discharge, burning | Mostly none; discharge, burning, spotting |
| Symptoms in men | Often none; some discharge/burning | Burning, white/yellow/green discharge |
| Preferred test | NAAT | NAAT |
| First-line treatment | A short course of doxycycline pills | A single ceftriaxone injection |
| Test-of-cure needed? | Not routinely; retest in a few months | Throat infections need a test-of-cure |
Testing for both
For both infections, the nucleic acid amplification test (NAAT), which detects bacterial DNA, is the recommended method, and it works on genital and extragenital (rectal and throat) samples CDC 2021 Guidelines. For gonorrhea, NAAT sensitivity is usually above 90% with specificity around 99%, so it rarely misses a real infection and rarely flags one that isn't there Clin Infect Dis.
In practice, testing is straightforward: a urine sample, a self-collected swab, or a quick exam depending on which site is being checked. It's free or low-cost at health departments, Planned Parenthood, and Title X clinics. A single test panel can screen for both at once. If you're not sure where to start, you can get tested through a standard panel, and timing matters — see when to test after exposure so you don't test too early and get false reassurance. For more on what gonorrhea results look like and how the different sample types compare, see our guide to the gonorrhea test.
Treatment compared
This is where the two diverge, and it's the most practical reason to get an actual diagnosis rather than guess.
Chlamydia is treated with doxycycline 100 mg orally twice daily for 7 days as the preferred regimen CDC. The 2021 guidelines moved away from the older single-dose azithromycin because a randomized trial found doxycycline cleared rectal chlamydia far better — a 100% cure with doxycycline versus 74% with azithromycin CID RCT. Finishing the full course is where people slip up; stopping early because symptoms eased can leave the infection behind.
Gonorrhea is treated with a single intramuscular injection — ceftriaxone 500 mg for most people, or 1 g for those weighing 150 kg or more — which covers urogenital, anorectal, and throat sites in one dose CDC. Azithromycin was dropped from gonorrhea treatment because resistance climbed fast: isolates with elevated azithromycin MICs rose from 0.6% in 2013 to 4.6% in 2018, leaving the single ceftriaxone shot as the lone first-line regimen. Throat gonorrhea is harder to cure — even fully susceptible pharyngeal infections failed ceftriaxone about 4.6% of the time — so a test-of-cure 7–14 days later is advised for throat infections specifically.
Treating partners measurably reduces repeat infection. In a landmark trial, giving patients medication to deliver to their partners (expedited partner therapy) cut persistent or repeat infection, with the biggest benefit for gonorrhea — 3% versus 11% NEJM. Whatever the diagnosis, your partners need treatment too, or you'll catch it back.
Can you have more than one at once?
Yes — co-infection is common enough that clinicians plan for it. When gonorrhea is diagnosed or strongly suspected, many providers treat for chlamydia at the same time, because the two routinely co-occur and the symptoms can't separate them. A comprehensive panel checks for both for the same reason: a single positive for one infection is a flag to confirm the other rather than assume it's absent. If you're treated and then re-exposed by an untreated partner, you can be reinfected within weeks, so retesting after treatment matters — read more on chlamydia reinfection and how soon to retest.
When to see a clinician
See a clinician if you have any new burning on urination, unusual discharge, pelvic or testicular pain, bleeding between periods, or if a partner tells you they tested positive. Because both infections are so often silent, symptoms won't reliably warn you, and routine screening matters even when you feel fine. Untreated, both can ascend and cause lasting harm: in women, pelvic inflammatory disease (infection of the upper reproductive tract that can scar the tubes and threaten fertility), and in men, epididymitis (inflammation of the coiled tube behind the testicle that can affect fertility). Getting tested and treated early prevents nearly all of that.