Recently there has been a growing interest in measuring hair cortisol level. Hair grows approximately 1 centimeter per month, and hair analysis accurately reflects long-term endogenous production of cortisol. This provides for the first time a reliable mode for the measurement of the accumulation of cortisol over time and a potential biomarker of chronic stress. Indeed, several reports have demonstrated an association between high hair cortisol levels and chronic stress in both animal models and in humans. Nevertheless, the possible association between hair cortisol and the risk of acute MI has not been studied yet.