The first time you probably heard the term sexually transmitted disease (STD) was in the awkward years of middle school in a mandatory health class that everyone dreaded. The classroom echoed with giggles and eyes roamed about! The teacher saying words like "chlamydia" and "discharge" made you want to put your head down and dream of escaping the torture. The teacher went on to review safe sex practices sandwiched between information on where babies come from and the lowdown on pubescent changes of both yours and the opposite sex. You thought your life was over.

Moving forward a few years, now everyone is calling them sexually transmitted infections, or STIs! Your middle school self is confused and can't understand the change. What exactly is an STI and how does it differ from the well-known term STD?

The terms STD and STI are often used interchangeably, but they technically mean different things. Both terms still represent the same group of viruses and conditions – gonorrhea is still gonorrhea and herpes is still herpes! The one major difference is between the "D" and the "I". Think back to nursing school basics where we learned the difference between a disease and an infection. Simply, an infection, often the first step, occurs when bacteria, viruses or other microbes that cause disease enter your body and begin to multiply. A disease occurs when the cells in your body are damaged – as a result of the infection – and signs and symptoms of an illness appear.

The main take-away is that one has symptoms (STD), and the other one does not (STI). You can have infections without symptoms, as seen with chlamydia, and that is why the term STIs has become more mainstream. It is much broader and more encompassing and now able to incorporate certain infections—such as herpes virus or human papilloma virus (HPV)—where a large proportion of infected persons are asymptomatic. Typically, a woman with HPV does not have any symptoms, but she carries the virus.  She has an STI; but if she develops cervical cancer from HPV, she now has an STD since cancer is a disease.  The same holds true for women who have chlamydia or gonorrhea that develops into pelvic inflammatory disease.

Another benefit for the change is to hopefully remind people that STIs often have no symptoms and to remember how important it is to have routine testing. I encourage testing not only at problem visits but at all annual visits and remind my patients of the importance of routine testing and safer sex practices.