Chlamydia and gonorrhea are both common bacterial STIs that often cause no symptoms, and when they do, they look almost identical: discharge and burning urination. The same urine test usually checks for both. Treatment differs: chlamydia takes a week of oral antibiotics, while gonorrhea needs an antibiotic injection because of drug resistance.
What chlamydia and gonorrhea have in common
Both are caused by bacteria — chlamydia by Chlamydia trachomatis and gonorrhea by Neisseria gonorrhoeae. They infect the same places (the genitals, rectum and throat) and spread the same ways, through vaginal, anal and oral sex. Most of the time they cause no symptoms, so people pass them on without knowing.
When symptoms do show up, they overlap heavily. Both can cause abnormal discharge and painful urination (dysuria, the burning sting during peeing). You can't reliably tell the two apart by symptoms, so you need a lab test. They're also screened for together: the U.S. Preventive Services Task Force recommends routine chlamydia and gonorrhea screening for sexually active women under 25 and others at higher risk USPSTF.
Chlamydia vs gonorrhea: the key differences at a glance
~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 |
| Chlamydia | Gonorrhea | |
|---|---|---|
| Bacterium | Chlamydia trachomatis | Neisseria gonorrhoeae |
| US cases (2023) | ~1.6 million reported | ~601,000 reported |
| Typical discharge | Clearer or cloudier, milder (when present) | Thicker, pus-like, yellow-green |
| First-line treatment | A week of oral pills (doxycycline) | A single antibiotic injection (ceftriaxone) |
| Antibiotic resistance | Not a major problem | Rising — closely tracked by the CDC |
| Test-of-cure | Not routine | Recommended for throat infections |
Symptoms compared
Neither infection is loud. Many people carry chlamydia or gonorrhea with zero symptoms, so screening matters. When symptoms appear, they tend to show up within days to a couple of weeks of exposure.
The classic shared signs are discharge from the penis, vagina or rectum, and burning during urination. Rectal infection can cause itching, discharge or discomfort; throat infection is usually silent. There's one rough pattern. Gonorrhea discharge tends to be thicker, more purulent (pus-like) and yellow-green, while chlamydia discharge, when it's there at all, is often clearer or cloudier and milder. Don't lean on that. It isn't reliable enough to diagnose either one, and people are commonly wrong about which they have. For a closer look at what men notice, see chlamydia symptoms in men.
How they're tested — usually the same test
In practice you don't choose between the two. The standard panel runs a single NAAT (nucleic acid amplification test) on one urine sample or swab and checks for chlamydia and gonorrhea together, with results typically back in one to three days. Because the bacteria take time to become detectable, test about two weeks after a possible exposure. If you've had oral or anal sex, ask for throat and rectal swabs, because a urine test alone won't catch an infection at those sites. You can get tested at a clinic, many pharmacies, or with an at-home kit.
How treatment differs — the real practical difference
This is where the two part ways, and patients feel the difference. Chlamydia is reliably cured by a short course of oral antibiotics — doxycycline 100 mg twice daily for 7 days CDC 2021 Guidelines. Gonorrhea is treated with a single intramuscular injection of ceftriaxone (500 mg, or 1 g for people who weigh 150 kg or more).
Oral antibiotics for gonorrhea are no longer dependable because the bacterium has grown resistant to them, so the injection is the only recommended first-line treatment. Chlamydia hasn't developed resistance in the same way, so pills still work. The CDC's 2021 guidelines simplified gonorrhea treatment to ceftriaxone alone, dropping azithromycin, which was being lost to resistance; doxycycline is added only if chlamydia hasn't been ruled out.
Ceftriaxone is a thick injection given in the buttock or thigh. It can sting and leave the spot sore for a day or two, and clinics usually have you wait around 15 minutes afterward to watch for an allergic reaction. If you're allergic to cephalosporins, tell your provider, and an alternative regimen such as gentamicin plus azithromycin is used instead. Throat (pharyngeal) gonorrhea is harder to clear because antibiotics penetrate throat tissue poorly, so the CDC recommends a test-of-cure about one to two weeks after treatment. Pharyngeal chlamydia doesn't carry that routine follow-up. Full doses live on our treatment pages: pills for chlamydia, a shot for gonorrhea.
Can you have both at once?
Yes, and it's common enough that clinicians plan around it. When someone has gonorrhea, a substantial share also carries chlamydia; by some estimates 10–30% are co-infected. So a provider may treat you for both at the same time, especially before all your results are back. If you test positive for one, ask whether you were checked for the other.
Complications of each
Left untreated, both infections can do real, lasting damage, so screening matters even when you feel fine. In women, both can cause pelvic inflammatory disease (PID), an infection that spreads to the uterus and fallopian tubes and can scar them, leading to chronic pelvic pain, ectopic pregnancy and infertility. In men, both can cause epididymitis, inflammation of the coiled tube behind the testicle, which is painful and can affect fertility.
Gonorrhea carries one complication chlamydia generally doesn't: it can rarely spread through the bloodstream to cause disseminated gonococcal infection (DGI), which brings joint pain, scattered skin sores and fever. Gonorrhea's resistance also makes it the bigger long-term worry, since ceftriaxone-resistant and extensively drug-resistant strains are still rare but are reported and tracked. If your symptoms persist after treatment, go back for a culture and a test-of-cure.
Prevention and partner treatment
Condoms cut transmission, and regular screening catches the silent infections before they cause harm. Treat your partners, or they'll reinfect you. Expedited partner therapy, where your provider gives you a prescription or medication to pass to your partner, is allowed in most states and measurably reduces repeat infection NEJM EPT trial, with the biggest benefit seen for gonorrhea. Avoid sex until both you and your partners have finished treatment.
When to see a clinician
See a provider if you have new discharge, burning urination, pelvic or testicular pain, rectal discomfort, or a partner who tested positive, even if you feel fine. Test about two weeks after a possible exposure, and don't wait for symptoms, since most infections cause none. If symptoms don't clear after treatment, return for a culture and test-of-cure rather than assuming it worked.