Trichomonas refers to Trichomonas vaginalis, a protozoan parasite that causes trichomoniasis, a common sexually transmitted infection (STI). Trichomoniasis is spread through vaginal, oral, or anal sex, and can also be transmitted by genital touching or sharing sex toys. Many people infected with trichomonas do not show symptoms, but when symptoms do appear, they usually start within 5 to 28 days after exposure. Symptoms in women can include itching, burning, redness or soreness in the genital area, discomfort while urinating, and a thin, often foul-smelling vaginal discharge which can be clear, white, yellowish, or greenish. Men are often asymptomatic but may experience itching inside the penis, burning during urination or ejaculation, and discharge from the penis. Trichomoniasis increases the risk of getting or spreading other STIs, including HIV, and can cause complications in pregnancy such as premature birth and low birth weight. The infection is diagnosed by detecting the parasite in vaginal fluid, urine, or by DNA tests. Treatment is with antibiotics such as metronidazole or tinidazole, and sexual partners should be treated simultaneously to prevent reinfection. It is a very common infection worldwide, affecting millions annually, with higher prevalence in women than men. Overall, Trichomonas vaginalis is the parasite responsible for trichomoniasis, a curable but common STI caused by a protozoan parasite transmitted primarily through sexual contact. This explanation provides a comprehensive overview of what trichomonas is and the infection it causes. If you want, I can provide more details on symptoms, transmission, diagnosis, treatment, or prevention.