Respiratory impairment is a broad term used to describe any reduction in the ability to oxygenate the body and to remove carbon dioxide from the body. Anything that interferes with these processes is considered a respiratory disease. Respiratory disease can be acute (short-term) or chronic (long-term or lifelong). All respiratory diseases, regardless of type, cause shortness of breath (SoB). Respiratory viruses and bacterial infections, such as the flu and bacterial pneumonia, are examples of acute respiratory disease. Emphysema and idiopathic pulmonary fibrosis are examples of chronic respiratory disease.
Respiratory diseases fall into two broad categories: diseases of the lung and airway tissue, and thoracic cavity respiratory disease. Diseases of the lung and airway tissue are further divided into two subgroups: obstructive lung disease and restrictive lung disease. Combined, these represent the three primary classifications of respiratory impairment: obstructive lung disease, restrictive lung disease, and thoracic cavity respiratory disease.
What is Obstructive Lung Disease?
Obstructive lung disease includes conditions that impair breathing by obstructing airflow out of the lungs when breathing out. People with obstructive lung disease cannot fully empty their lungs, which is sometimes referred to as air trapping. This leads to hyperinflation, where the lungs remain partially inflated before the next breath begins. Examples include emphysema, chronic bronchitis, and bronchiectasis.
What is Restrictive Lung Disease?
Restrictive lung disease includes conditions that impair breathing by restricting airflow into the lungs when inhaling. People with restrictive lung disease cannot fully fill their lungs with each breath, leading to hypoinflation. Restrictive lung disease often reduces lung distensibility, or the ability of lung tissue to expand. As a result, total lung capacity may decrease. Examples include sarcoidosis, idiopathic pulmonary fibrosis, and pleurisy.
What is Thoracic Cavity Respiratory Disease?
Thoracic cavity respiratory disease refers to breathing conditions caused by a reduced ability to fully expand the chest cavity with each breath. A defining feature of this category is that lung and airway tissues are healthy. Airflow into the lungs is not restricted, and airflow out of the lungs is not obstructed. Instead, the chest cavity cannot expand enough to allow the lungs to fully inflate, resulting in hypoinflation. The type of respiratory impairment CMT can cause is an example of thoracic cavity respiratory disease.
Why These Matter in CMT
CMT does not damage lung or airway tissue. When CMT affects breathing, it does so by limiting chest expansion due to the breathing muscles becoming weakened. This placed it firmly within the definition of thoracic cavity respiratory disease.
