The test for syphilis, a sexually transmitted infection brought on by the bacteria Treponema pallidum, is called the VDRL Test (Venereal Disease Research Laboratory Test), sometimes referred to as RPR (Rapid Plasma Reagin). It functions by identifying antibodies that the body makes in reaction to the infection. The test consists of combining a reagent containing cardiolipin, a material present in some bacteria’s cell membranes, with a patient’s blood serum. A noticeable clumping or “flocculation” reaction will occur when cardiolipin and syphilis antibodies interact in the blood. Positive findings suggest the existence of syphilis antibodies and can call for additional testing to confirm the results. The addition of “(HHD)” designates the unique setting or version of the exam, possibly referencing a specific medical professional or