Common respiratory diseases include asthma and chronic obstructive pulmonary disease, or COPD, according to MedlinePlus. Asthma is the inflammation of a person's airways, which causes shortness of breath, and COPD is the inability to exhale completely, according to WebMD.
Another common respiratory disease is emphysema, according to WebMD. Emphysema is a type of COPD that results from lung damage. This damage traps air in the lungs, making it difficult to exhale. Cystic fibrosis is another respiratory disease that causes mucus in the lungs to clear slowly. This often results in repeated lung infections. Finally, pneumonia, another respiratory disease, is an infection of the lung's alveoli, often caused by bacteria.