Gonorrhea is very common, having been known for centuries by the slang term “the clap.” It is worldwide in distribution, though the incidence is not precisely known because of self-treatment, undiagnosed cases, and defective reporting. In the United States, for instance, fewer than a half million cases are reported each year, but this figure may reflect only 50 percent of actual cases. Occasional increases have been seen since the mid-1990s; these have been attributed in part to the growing resistance of N. gonorrhoeae to penicillin. The mortality from gonorrhea is negligible, but its indirect effects on the population by its not infrequent sterilization (infertility) of both sexes are incalculable.

The incubation period of gonorrhea is usually 3 to 5 days (range 2 to 10 days). The first symptoms in the male are a burning sensation upon urination and a purulent urethral discharge that may be profuse or may be so meagre as to go unnoticed. In the absence of treatment, the infection usually extends deeper, to involve the upper urethra, the neck of the urinary bladder, and the prostate gland. Urgency and frequency of urination and, occasionally, blood in the urine may follow. Spontaneous recovery may occur within a few months to a year. Particularly among homosexual or bisexual men, rectal gonorrhea may appear with pain in the perianal area and a mucous coating on the stool.

The initial symptoms in the female are, in most instances, so mild as to go unnoticed. Slight vaginal discharge with burning may occur. The disease is not usually suspected by either patient or physician until complications arise or a sexual partner is infected. Abscess of a vulvovaginal (Bartholin) gland occurs rarely as an early complication. Many women recover spontaneously from gonorrheal infections that extend no farther than the uterine cervix (mouth of the uterus). In many cases, however, the infection extends through the uterus to the fallopian tubes (fallopian tube) and ovaries (ovary)—a condition known as pelvic inflammatory disease. Fever usually accompanies this extension, and lower abdominal pain is a prominent symptom. Pelvic abscess or peritonitis may result. The symptoms can be confused with those of appendicitis. Healing occurs without resort to surgery in most cases, often with some physical disability and sterility. In immature girls the infection is usually confined to the vagina.

N. gonorrhoeae can sometimes enter the bloodstream, causing disseminated gonococcal infection (DGI) in virtually any organ system. In both male and female, arthritis is the most common manifestation of DGI. The process usually settles in one or two joints and may result in permanent disability in the absence of treatment. Involvement of the tendon sheaths in the region of the affected joint or joints is not uncommon. Other, very rare, complications of gonorrhea are iritis (inflammation of the iris), endocarditis, meningitis, and skin lesions.

Diagnosis is established by culture of a sample of urine or discharge. penicillin or tetracycline is the antibiotic usually used in treatment, one injection usually being sufficient to cure uncomplicated gonorrhea. Strains of gonococci that are resistant to penicillin or tetracycline are on the increase, however, and spectinomycin or cefoxitin are increasingly used as alternative drugs in eliminating these bacteria.

The administration of smaller amounts of penicillin and most other antibiotics sufficient to cure gonorrhea may mask the early manifestations of coexisting syphilis and delay its diagnosis. An integral part of the treatment of gonorrhea, therefore, is the so-called serological (serological test) follow-up—a blood test for syphilis at least once a month for four months.