What types of things cause shortness of breath in nonasthmatic teen?

Normal or not? Since everybody becomes short of breath with exertion, it should first be determined if this is normal. Valvular and congenital heart disease, and various non-asthmatic lung diseases cause pathological breathlessness. Specific cardiac examples include: rheumatic heart disease (mitral stenosis), dilated or hypertrophic cardiomyopathy, and a large variety of congenital defects.