Reactive, non-reactive, indeterminate, equivocal, STD test results come wrapped in clinical vocabulary that can turn a routine screen into a spiral of worry. The interactive tool below decodes what your specific result means for each infection, and the sections that follow explain the words themselves and why a reactive screen is not the same as a diagnosis.

Result words, in plain English

Labs and clinics don't always say “positive” or “negative.” Here is what the terms you'll actually see on a report mean.

  • Reactive / non-reactive, the screening-test version of positive / negative. “Reactive” = a signal was detected (preliminary positive); “non-reactive” = none (negative). Reactive screens usually need a confirmatory test.
  • Positive / negative, positive = the infection (or its marker) was detected; negative = it wasn't. How final that is depends on the test and the window period.
  • Indeterminate / equivocal / inconclusive, the test couldn't call it either way, borderline sample, very early infection, or a nonspecific reaction. Not a diagnosis; repeat or confirmatory testing follows.
  • Titer, a number (e.g., an RPR titer for syphilis) showing how much of a marker is present, used to judge how active an infection is and to track treatment.
  • Window period, the gap after exposure before a test can reliably detect an infection. A negative taken inside the window can be a false negative.

A reactive screen is not yet a diagnosis

For HIV, syphilis, and hepatitis C, screening tests are deliberately tuned to catch every possible case, which means they occasionally flag people who aren't infected. That's why a reactive screen is followed by a second, more specific confirmatory test before anything is confirmed. If you get a reactive screening result, the right next move is the confirmatory test, not conclusions.

By contrast, the NAAT tests used for chlamydia, gonorrhea and trichomoniasis are highly specific, so a positive is very reliable, and all three are curable. Either way, a clinician interprets the result in context.

Keep exploring on EasySTD: which STD test you need, when to re-test and HIV/AIDS testing.