There are more than a hundred subtypes of mycoplasma, and the ones that are relevant to humans are Mycoplasma pneumoniae, Mycoplasma urealyticum, Mycoplasma hominis, and Mycoplasma genitalium. Mycoplasma pneumoniae can cause pneumonia, and Mycoplasma urealyticum can cause nongonorrhea. Mycoplasma hominis can normally parasitize the vagina and the external urethra, and can cause nongonorrhea symptoms when the body is immunocompromised. Mycoplasma hominis can retrogradely infect the prostate, seminal vesicles, vas deferens and epididymis, and parasitization on the seminal tract can cause a decrease in the number of spermatozoa viability and affect fertility. Generally simply from the urethra or vaginal examination of Mycoplasma hominis, there is no infection infection symptoms, no need for treatment, as long as the existence of infection symptoms, it should be timely treatment.