“The clap” is a common slang term for gonorrhea, one of the most widespread sexually transmitted infections in the world. It’s caused by a type of bacteria that infects the lining of the reproductive tract, throat, or rectum. The nickname has been in use since at least 1719 and may come from the old French word “clapier,” meaning brothel, where the infection spread easily. A less pleasant theory suggests it refers to an old treatment method that involved clapping the penis between two surfaces to force out infected discharge.
What Causes Gonorrhea
Gonorrhea is caused by bacteria that exclusively infect humans. The bacteria target the moist, warm tissue lining the reproductive tract, and can also take hold in the throat, eyes, and rectum. Once the bacteria reach these surfaces, they use specialized structures on their outer membrane to latch onto cells, penetrate the tissue lining, and trigger inflammation. The infection process actually differs between men and women at a cellular level, but the end result is the same: the bacteria colonize the tissue and begin multiplying.
The infection spreads through vaginal, anal, or oral sex. You can get it from any of these routes, and a person can pass it on even when they have no visible symptoms. A pregnant person with gonorrhea can also transmit it to their baby during delivery.
Symptoms in Men
Men tend to develop noticeable symptoms more often than women. The most common signs include a burning sensation when urinating and a white, yellow, or green discharge from the penis. Some men also experience painful or swollen testicles, though this is less common. Symptoms typically appear within a few days of exposure, but some men carry the infection without knowing it.
Symptoms in Women
Most women with gonorrhea have no symptoms at all. When symptoms do appear, they tend to be mild and easy to confuse with a bladder infection or yeast infection. They can include painful urination, increased vaginal discharge, and bleeding between periods. This is one of the reasons gonorrhea is so effective at spreading: the majority of women who have it don’t realize anything is wrong.
Rectal and Throat Infections
Gonorrhea in the rectum may cause discharge, anal itching, soreness, bleeding, or painful bowel movements. It can also cause no symptoms whatsoever. Throat infections from oral sex are usually asymptomatic too, which means people can unknowingly transmit the bacteria from a site they didn’t even know was infected.
What Happens If It Goes Untreated
Left untreated, gonorrhea can cause serious and sometimes permanent damage. In women, the bacteria can travel upward from the cervix into the uterus and fallopian tubes, causing pelvic inflammatory disease (PID). An estimated 10% to 20% of untreated infections progress to PID. The resulting inflammation damages tissue and creates scarring that can block the fallopian tubes, leading to chronic pelvic pain, ectopic pregnancy, and infertility. Delayed treatment is directly linked to worse fertility outcomes.
What makes this especially dangerous is that PID doesn’t always announce itself. A form called subclinical PID can cause inflammation in the upper reproductive tract without triggering the acute pain you might expect. Women with this silent version still face a significant risk of infertility compared to those without it, but they may never know the damage is happening until they try to conceive.
In men, untreated gonorrhea can cause a painful infection in the tubes connected to the testicles, which in rare cases leads to infertility. In both sexes, the bacteria can occasionally enter the bloodstream and spread to joints and other organs, a condition that requires urgent medical treatment.
How It’s Diagnosed
The most accurate test for gonorrhea is a nucleic acid amplification test (NAAT), which detects the genetic material of the bacteria. It can be performed on a urine sample or a swab from the infected site (throat, rectum, cervix, or urethra). NAATs are highly sensitive and can be done without waiting a full 48 hours after exposure, since they can pick up even small amounts of bacterial DNA.
Doctors sometimes also use a culture test, which is less sensitive but has one major advantage: it can reveal which antibiotics the bacteria are resistant to. That information is becoming increasingly important.
Treatment and the Resistance Problem
Gonorrhea is curable with antibiotics, typically a single injection. If a chlamydia co-infection hasn’t been ruled out, an additional oral antibiotic course may be added. Most people clear the infection without complications when it’s caught early.
The bigger concern is that gonorrhea is rapidly outpacing the drugs used to treat it. A November 2025 report from the World Health Organization found that resistance to the primary antibiotic used against gonorrhea jumped from 0.8% of tested cases in 2022 to 5% in 2024. Resistance to a related backup drug climbed from 1.7% to 11% over the same period. Resistance to an older class of antibiotics has reached 95%, making those drugs essentially useless. Cambodia and Vietnam reported the highest resistance rates, but resistant strains are being detected in more countries each year.
This trend means that a future where gonorrhea is difficult or impossible to treat with existing drugs is not hypothetical. It also means that if you’re treated for gonorrhea and symptoms don’t resolve, follow-up testing is important to confirm the infection is actually gone.
Who Gets It
Gonorrhea can affect anyone who is sexually active. Data from a 2024 WHO surveillance effort across 12 countries found a median patient age of 27. Among reported cases, 20% were men who have sex with men, and 42% reported having multiple sexual partners in the past 30 days. About 19% had traveled recently, highlighting how the infection (and its resistant strains) move across borders.
Reducing Your Risk
Condoms significantly reduce the risk of transmission during vaginal and anal sex. For oral sex, dental dams or condoms offer some protection, though they’re used far less consistently in practice. Because gonorrhea so often causes no symptoms, regular screening is the most reliable way to catch an infection early, especially if you have new or multiple partners. Testing is quick, usually just a urine sample, and early treatment prevents the complications that make gonorrhea dangerous in the first place.