Trichomoniasis is a sexually transmitted infection caused by the parasite Trichomonas vaginalis, primarily affecting the urogenital tract, leading to vaginitis in women and urethritis in men. Symptoms typically appear 5 to 28 days post-infection, including various types of discharge and discomfort, with potential complications like preterm delivery and increased susceptibility to HIV. Diagnosis requires a swab of vaginal fluids, treatment with metronidazole is highly effective, and prevention strategies include condom use and open communication about sexual health.