Final answer:
The severity of obstruction in diseases like emphysema and asthma can vary with the loading condition. In obstructive lung diseases, the airways are partially or completely blocked, reducing the flow of air in and out of the lungs. The severity of the obstruction can worsen with increased physical activity or exercise.
Step-by-step explanation:
The severity of obstruction varies with the loading condition in diseases like emphysema and asthma. In obstructive lung diseases, the airways are partially or completely blocked, reducing the flow of air in and out of the lungs. The severity of the obstruction can worsen with increased physical activity or exercise, which increases the demand for oxygen and puts more stress on the obstructed airways.
For example, in asthma, the severity of obstruction can vary depending on the triggers and the individual's response to them. During exercise or physical exertion, the airways can constrict, leading to a more severe obstruction and symptoms like wheezing and shortness of breath.