The vagus nerve is the tenth cranial nerve that travels from the brain down to the abdomen, branching out to visit many organs on the way. It conveys sensory information to the central nervous system. You may not know it, but the vagus nerve is your friend and it would be highly beneficial for you to get to know it.
Why learn about this hidden part of our anatomy? Because the vagus nerve acts as the “off switch” for stress. By stimulating this nerve we instantly bring ourselves from a heightened state of arousal to one of calm awareness.
Western medicine has invented a device similar to a pacemaker that can be surgically implanted which stimulates one side of the vagus nerve with electrical pulses. It's used in certain cases of epilepsy and has been approved for use in depressed patients who are not responding to medication. Luckily, however, we can all benefit from naturally stimulating the vagus nerve without resorting to expensive surgery.
Try this – breathe in to a count of six, hold for three, breathe out for nine. While doing this, constrict the glottis at entrance to the throat (you engage the muscle this way when you swallow, or when you fog up the lenses of your glasses to polish them), both on the in breath and on the out breath.
This is called “pipe breathing”, and it is specially designed to stimulate the vagus nerve, putting a stop to stress in the moment. How handy!