It is the nature of the human mind to seek out stimuli, to make order and sense of the world we live in.  That drive can also work against us.  In situations of stress, our mind can become overrun with competing sensations and feelings.  All jammed together, these turn into those nasty anxiety reactions we've all been victim to one time - or many.  

As stated, there's a weapon in your arsenal that you can use to combat anxiety - mindfulness.  Mindfulness, put simply, is the practice of stopping and considering the present moment, to the exclusion of all else.  This can be done in a number of ways, but at its core, the idea is pretty easy to understand: take yourself out of the moment, "out of your own head," so to speak, and back into the world as it truly is.  When you practice mindfulness, you're transferring control from the erratic workings of your mind back into your conscious hands.   

The beauty of mindfulness is that it can be practiced anywhere, at anytime.  Simply ground yourself in the moment and focus on the things under your control, such as your breathing.  Take slow, deep breaths in and out.  With your eyes and other senses, focus on clear, simple things in your environment. 

How many leaves are on the ground?  Feel and appreciate the air on your skin.  Pick a point in the room and focus on as many small details as you possibly can - anything to take your mind out of the overwhelmed state it's in and bring the focus back to something simple.  Do this for long enough, and you'll notice that your breathing has regulated, your heart rate has lowered and (hopefully) your overall sense of wellness is improved.

Will mindfulness work all the time, every time?  No, unfortunately not.  There are always times that our stresses get the better of us.  The important thing isn't to remember our failures, but to keep trying.  Give it a chance, and mindfulness will bring you back to feeling centered and well.