Interstitial Lung Disease
Airway diseases can be classified as either obstructive or restrictive. Obstructive airway disease makes it difficult to exhale all the air from the lungs, while restrictive airway disease prevents the lungs from expanding to accommodate more air. Both obstructive and restrictive airway diseases have two common symptoms namely; exertion and shortness of breath. However, the two types of airways diseases have got some differences in signs and symptoms (Mannino, Ford and Redd, 2003).
The most common symptom of restrictive and obstructive airway diseases is cough. The cough is normally dry or may produce white sputum. People with severe cases of restrictive and obstructive lung diseases may present with coughs with huge amounts of colored sputum. Shortness of breath is also observed among people with obstructive and restrictive lung diseases (Mannino, Ford and Redd, 2003). Other symptoms of restrictive and obstructive airway diseases are anxiety and depression. These symptoms are observed when the disease condition brings about change in lifestyle and activity. In order to confirm presence of restrictive lung disease and rule out that of obstructive airway disease, the patient needs to have the above named symptoms together with progressive exertional dyspnea. Determination of the level of dyspnea can help in telling the severity of the symptoms. People with restrictive airway disease also present with wheezing caused by the forceful breathing. Chest pain is another symptom of restrictive lung disease (Mannino, Ford and Redd, 2003).
Any condition that results into stiffness in the lungs causes restrictive airway disease. Such conditions may also cause stiffness of the chest muscles and damaged lungs, thereby restricting the lung from expanding. A number of conditions are believed to be the common causes of restrictive airway disease and they include sarcoidosis, interstitial lung disease, obesity, scoliosis, and neuromuscular diseases such as amyotrophic lateral sclerosis or muscular dystrophy. Restrictive lung disease may also occur from inhalation of large volume of dirt normally associated with occupation (Mannino, Ford and Redd, 2003).
Normally, reduced total lung capacity is the main feature of restrictive lung disease. Total lung capacity refers to the amount of air available in the lungs after taking the deepest possible breath. When restrictive airway disease in present, the lungs are prevented from expanding fully and a person cannot take a complete breath. Diagnosis of restrictive airway disease can therefore be achieved by measuring the total lung capacity because it gives the correct information about the existence of a true restriction. In addition, measuring the total lung capacity helps the physician to quantify the extent of restriction (Gulati, 2011).
Total lung capacity can be obtained by adding the vital capacity to the residual volume of air. Residual volume of air refers to the amount of air that remains in the lungs after a deep exhalation, and the vital lung capacity is the amount of air that a person exhales in one breath. Vital lung capacity may also be defined as the maximum amount of air that a person can forcibly exhale after taking the deepest possible breath. Total lung capacity is measured by carrying out a laboratory test. Restrictive airway disease can also be diagnosed using imaging tests such as Chest X-ray film and Computed Tomography of the chest. The doctor may also recommend a bronchoscopy in some people to diagnose restrictive lung disease. When conducting a bronchoscopy, an endoscope is used to check inside the airways and obtain samples of lung tissue (Gulati, 2011).