The term vagal tone refers to the activity of the vagus nerve, which is an indicator of parasympathetic nervous system activity. The vagus nerve is a complex of cranial nerves that originates at the base of the brain and passes through the trunk, branches out like a tree, and sends out stubs to communicate with the internal organs and glands. 1 When we speak of the undeniable power of the mind-body connection, we are usually referring to the action of the vagus nerve. A decrease in heart rate, respiratory rate, and blood pressure indicates increased activity of the parasympathetic nervous system and therefore may also serve as an indicator of vagal tone. The vagus nerve transmits information between the brain and the lungs to regulate breathing. 2 When you are not stressed, your breathing is naturally slow and controlled. However, there is increasing evidence that we can tell the vagus nerve that we are relaxed when we consciously breathe as if we are not stressed. The vagus nerve transmits this information to the brain, and voila, we have created our own relaxed reality. The vagus nerve is the heart of the parasympathetic nervous system. It gathers information from your organs and translates it into messages that tell your brain, “Everything’s fine here,” or “Oops, something’s wrong. It’s time to turn on the sympathetic nervous system. It also sends instructions from the brain to the body. So there is a growing interest in the vagus nerve and how we can use it to relieve the chronic stress so prevalent in modern life. Some people think of the vagus nerve as a brake on the sympathetic nervous system, but I disagree with that analogy. Research shows that we can intentionally activate the vagus nerve and thus relieve physiological stress. When you begin to improve your vagal tone and feel calmer, less stressed, better regulate your emotions, it becomes self-enhancing. These are usually downward or efferent processes, which means that the brain controls these physiological processes through the vagus nerve. Simply put, the vagus nerve modulates the response to stress and contributes to our ability to maintain homeostasis. In the long term, it seems possible to improve vagal tone and move to a more chronic state dominated by the parasympathetic system through regular breathing exercises. The good news is that many basic lifestyle habits can also improve vagal tone. My prediction now is that the vagus nerve will soon have its own sexy maiden summer, and I’m looking forward to it.