Trichomonas (also called trichomoniasis) is not a serious condition. This STI is more likely to cause symptoms in women than in men, and these may be an inflammation of the vagina, urethra or bladder. An infection may remain unnoticed for a long time because it gives no symptoms at all.
A trichomonas infection is easy to treat. Your partner should be tested and treated if necessary.
Use a condom for vaginal sex to prevent infection. It is better not to have sex during treatment (to prevent reinfection). If you do want to have sex, use a condom!