Effect of a sleepless night combined with 2 cups of instant coffee on heart rate variability in an elderly man

Insomnia is harmful and has negative effects on the human body. Coffee most commonly used beverage to invigorate. Measurement of heart rate variability accurate method for quantitative assessment sympatho-vagal balance autonomic nervous system, which determines adaptive capacity stress. In our Case Report, after 1 sleepless night, stress index rises sympathetic over parasympathetic prevails.