When you're under stress, your muscles tense, and your breathing becomes shallow and rapid. one of the simplest (and best) ways to stop this stress response is to breathe deeply and slowly. It sounds simple, and it is. Most of us, however, do not breathe deeply under normal circumstances, so it may help to review the mechanics of deep breathing and how it helps us
to relax

 
Breathing Under Stress:
 
When prehistoric humans were in danger of attack, their muscles tensed and their breathing became rapid and shallow, as they prepared to run or fight. Their high level of tension was a means of preparing their bodies for optimum performance. Today, the causes of our "stress" are different, but our stress response is the same. However, since we're not running or fighting, our tension has no release and our stress response builds. One way to counteract the stress response is to learn how to breathe deeply and slowly -- the opposite of how we breathe when under stress.

How Deep Breathing Works:
  
Deep breathing is not always natural to adults. Watch the way a baby breathes: the area beneath the chest goes in and out. Most adults breathe from the chest. This is shallower breathing, so less oxygen is taken in with each breath. As a result, the blood is forced to move through the system quickly so that enough oxygen gets to the brain and organs. Higher blood pressure results.
 
Deep breathing can reverse these effects. Take some time to practice this kind of breathing each day, especially when you're under stress. You can be sitting, standing or Iying down, but it helps to wear loose, comfortable clothing. Begin by breathing in through your nostrils. Count to five silently saying the word "in " and let your lower abdomen fill with air. Then silently saying the word "out" as you let the all escape a pursed lips. Do this deep breathing for two minutes or more each time. With practice, you will be able to count slowly to 10 or higher; You can increase your relaxation if you imagine breathing in ocean air, the scent of flowers or forest air.

Effects of Deep Breathing:

By helping you let go of tension, deep breathing can relieve headaches, backaches, stomach aches and sleeplessness. It releases the body's own painkillers. called endorphins, into the system. It allows blood pressure to return to normal, which is good for your heart. Deep breathing can also allow held-in emotions to come to the surface, so your emotional health benefits from deep breathing, too. Use deep breathing any time, anywhere. It's one of the best techniques for relieving stress.