We need stress to perform better, the new research comes. I also favor to this, stress which is related with fulfillment of our duty, helps to open our brain nerves.  It increases alertness of mind, and also improves bowel movement. “It is both protective and damaging effects on the body” Mr. Zhen Yan study says.  I also have study on patients.  If stress should be in positive way, like duty related. Then it improves working memory, blood circulation etc.  I have seen on myself, when any emotion related job, like my family, social, and spiritual duty, comes into my mind then I become more alert and more active than before. So many ways comes into my mind for choosing. It gives me energy for doing more niskam karma. But I also have seen some times, when your stress converts into anxiety then it becomes serious. Because anxiety gives depression, and laziness ultimately. In this great world most of the people suffers this type of stress. These stresses have damaging effect on the body and mind.
I am going to give some important breathing and meditative exercises which will give you great benefit to come out from bad stress.
BREATHING EXERCISE; sit straight and comfortably in any meditative pose at peaceful, dark area. Now let check your nostril, which one is clearer than others. 
Example; if the right nostril is clearer than left, then close the right nostril from your any fingers, now start inhale with left nostril and exhale with same left.  Do it for ten minute continuously and thereafter practice with the other right nostril breathing for 5 minute.  You must be aware that you have to breathe from less clearer nostril more than others.
Mostly stress full people’s right nostril have more clear than left, that’s why they need to do breathing exercise from left nostril more.  
Anulom-vilom (alternate nostril breathing)
“by proper practice of pranayama etc, all diseases (mental or physical) are eradicated. Through improper practice all diseases can arise.”
yogi swatmaram states that alternate nostril breathing purifies the nadis (whole nervous system) within three month. If practiced properly.
Technique: sit in any comfortable meditative pose or on the chair, close the right nostril and inhale slowly, steadily and deeply through the left nostril, after full inhalation hold it for a while and now close the left nostril and exhale slowly steadily through the right nostril.  Slowly inhale again through the right nostril and exhale from the left. this is one round .let’s do this for 5 to 10 minutes with closed eyes.
Checkpoint: while practicing, be sure that there should be no strain on the face and the head and body do not tilt in any direction. if you have high blood pressure or heart trouble, then avoid holding breath exercises.

Effect: it helps to reduce the level of stress, frustrations, anxiety and hypertension.
UJJAI PRANAYAM:
Technique:
Sit in any comfortable and meditative pose with spine erect. Now close eyes and start with deep breathing, after some time focus consciousness on throat. Fold the tongue back and touch tip on palate and start breathing from throat.  You can take breath from mouth but if it is possible then take breath from nostril. But the most important thing is breathe from throat. During this pranayam produce sound like snoring. The sound of breath should not be very loud. In the beginning Inhale should with effort and exhale should be without effort. But after a month both Inhalation and exhalation should be with effort. Do practice it for 20 to 30 minutes. After completing ujjai start doing Anulom-vilom pranayam for 10 minute.   While breath in chest should be out with effort and breathe out chest in without effort.
  Best Time: One who wants to give up alprax should do this pranayam in the night before sleeping and in the morning empty stomach.     
Precaution:

Result: within weak addicted patient will get relief. After a month they shall give up addiction.