Many things can cause shortness of breath, but the most common are asthma, pneumonia, bronchitis, lung cancer, anxiety, an allergic reaction, a lung injury, obesity, heart dysfunction, COPD and many many more things.
As for treating this, see your physician. Hope I helped you!
Answer:
be careful who you hang around with, tell someone you fell pressured, take time for yourself, ask your parents, etc.
I would say, trunk flexion uses the most amount flexibility.
