**6. Complications**

Reinfection is common, and sequelae associated with complications are likely to increase with multiple infections. Untreated or inadequately treated patients may develop epididymitis and orchitis. These conditions can develop after urethritis or in the absence of urethritis. Symptoms are milder than with other causes of epididymitis [20]. It manifests with unilateral testicular pain, tenderness, and palpable swelling along with hydrocele and fever, whereas lymphogranuloma venereum presents clinically as a painless genital ulcer. The ulcer is typically small and star-shaped. After ulcer formation, inguinal lymphadenitis is also characteristic [29]. Testicular involvement can cause pyogranulomatous changes in the testicle. This may lead to testicular degeneration, resulting in serious andrological sequelae [20].

It can also cause serious complications such as chronic prostatitis/chronic pelvic pain and infertility. *C. trachomatis* has been the focus of attention in cases of chronic prostatitis/chronic pelvic pain of unclear etiology. Although the evidence is debatable, significantly more *Chlamydia* bacteria were reportedly detected in the urine, semen, and prostate fluid and tissue of patients with chronic prostatitis compared to the control group [10]. Studies on this subject are still ongoing, and its etiological role has not been fully clarified due to the diagnostic challenges.

Another serious complication of incomplete or untreated chlamydial infection is infertility. Asymptomatic persistent infection can negatively affect fertility in couples by causing chronic inflammation [11]. Studies evaluating the relationship between chlamydial infection and sperm quality have yielded conflicting results. Recent studies have generally demonstrated lower ejaculate quality in infected individuals. Persistent infection has been observed to cause scarring in the ejaculatory ducts and loss of stereocilia. In addition, some studies have associated infection with DNA fragmentation and sperm dysfunction, and death [10].

It should be kept in mind that chlamydial infections in women can also cause serious complications such as infertility, pelvic inflammatory disease, ectopic pregnancy, and Fitz-Hugh-Curtis syndrome [9]. *C. trachomatis* is also a common cause of symptomatic proctitis and proctocolitis in homosexual men [29].
