Breathing difficulty

I live in the UAE and i'm not sure if my breathing difficulty is because of the warmer weather that we have right now,or stress related or asthma or even heart problems.I have been experiencing breathing difficulties for a few days now ,i keep feeling that i have to take deep breath(not continously),i also feel a slight discomfort in my  middle back and on the sides of my middle back(lungs).I exercise every morning(elliptical,treadmill,weights) for about an hour and i'm fine during the exercise.I'm very worried,please can you give me some info on what might be the problem.
Thank you

[hava]

This will improve your breathing in a few days, and your stress will be reduced. Start today and come back to report your progress.
Build up your timing gradually. If you feel tired or dizzy, stop and resume after 1 minute.

Anulom Vilom –
Close your right nostril with thumb and deep breath-in through left nostril  
then – close left nostril with two fingers and breath-out through right nostril  
then -keeping the left nostril closed  deep breath-in through right nostril
then - close your right nostril with thumb and breath-out through left nostril.
This is one cycle of anulom vilom.
Repeat this cycle for 15 to 30  minutes twice a day).
You can do this before breakfast/lunch/dinner or before bedtime or in bed.Remember to take deep long breaths into the lungs.You can do this while sitting on floor or chair or lying in bed.