MEDFORD, Mass., US: Stress can present as a wide range of physical, emotional and social symptoms, such as irritability, headache, anxiety and elevated heart rate. In addition to these manifestations, salivary cortisol serves as a well-established biomarker of physiological stress, reflecting levels found in the bloodstream. Since stress is of a damaging and pervasive nature in the precarious, time-sensitive, incessant world in which we live, a tool capable of quickly and accurately measuring cortisol levels in saliva would be highly efficacious. As outlined in a recent study, a team of researchers at Tufts University in the US has developed a floss pick that can do just that.