Are all infections considered STD's?

I recently got a yeast infection, is this considered a sexually transmitted disease?  All information about yeast infections are inconclusive as to their origins.  Also If I have been having unprotected sex with my partner does he need to be treated as well, and how do they treat a yeast infection in a male?

[H. Hunter Handsfield, M.D.]

No, yeast infections are not sexually transmitted, with rare exceptions.  Yeast is a kind of fungus. Various species of yeasts/fungi (e.g., Candida and others) are normally present on and around various parts of the body, including the rectum and vagina; most women carry yeasts some of the time and in some women they are always present.  In other words, when a "yeast infection" occurs, it isn't that the yeast has newly arrived; it has been there all the time.  The reasons yeasts grow to larger amoungs, or that your body reacts to them with irritation, are quite varied and often aren't known--although hormonal fluctuations, changes in other bacteria in the vagina (e.g., after antibiotic therapy for another infection).

Having said all that, there are exceptions.  Occasionally a man may get a penile yeast infection by exposure to a woman with vaginal yeast; and on very rare occasion, a woman may acquire infection from a male partner.

I hope this helps.  Regards--   HHH, MD