Lately, you have probably seen “STD” and “STI” pop up to talk about the same things, such as Chlamydia and Gonorrhea. It may not be clear why one term is being used instead of the other, as often people use these terms interchangeably. Globally, the term STI (Sexually Transmitted Infection) has become more popular simply due to less stigma associated with the term ‘infection,’ compared to ‘disease.’
Another important difference between the two terms is that infections termed STIs are understood to occur in the absence of symptoms — key examples include certain forms/stages of Genital Herpes, Chlamydia, and Syphilis. On the other hand, STDs (Sexually Transmitted Diseases) typically refer to conditions in which various pathogens have caused symptoms and/or clinical signs. In general, there is overlap between these definitions such that most sexually acquired conditions fall into either category depending on the stage of illness.