Lung diseases may be classified as either obstructive or restrictive lung diseases. Obstructive lung diseases are basically lung diseases which make it difficult to breathe out. Restrictive lung diseases are cause difficulty in breathing in. Both of these classes of lung diseases have almost similar symptoms which are mostly shortness of breath and thus may be very hard to diagnose. The most common types of obstructive lung diseases include asthma, bronchitis, cystic fibrosis and chronic obstructive pulmonary disease.
A common symptom of obstructive lung diseases is the inability to breathe freely during increased exertion. During activity, as the rate of breathing increases, there is less time to breathe air out before the next inhalation causing shortness in breath. Obstructive lung diseases can be easily identified by a qualified doctor.
A doctor should carry out a pulmonary function test. The test involves the test subject to be placed in an enclosed booth and breathe through a mouthpiece. As the subject breaths, the volume of air inflow and outflow through the lungs is monitored and recorded.
Imaging tests like x rays and computer tomography (CT) scans are good methods of diagnosing obstructive lung diseases diagnosis. A CT scan be used to detecting even the tiniest of changes the lung parenchyma which are involved in exchange of gases between the respiratory and circulation system.
While x rays may be useful I detecting obstructive lung diseases, they only produce two dimensional pictures. A CT scan will produce a three dimension image of the lungs.
If a pre-existing condition should be causing obstructive lung diseases, a bronchoscopy will be recommended. A bronchoscopy involves use of an endoscope which consists of a camera connected to a flexible tube to look at the inside of the respiratory tract and take a sample tissue for further testing.
- Microbiological culture is also a common method of diagnosing obstructive lung diseases. This method involves multiplying organisms found on lung tissue in controlled laboratory conditions. This can be used to easily determine the type of organism contained in the tissue but may take a few days to complete.
- Perfusion scans are also a method of diagnosing obstructive lung diseases. It is commonly referred to as V/Q lung scans and uses various types of medical imaging including scintigraphy. Other medical imaging techniques like use of medical isotopes are a common in this procedure. These methods involve the use of radioisotopes and other nuclear material to be put in the patient and the radiation they emit be used to construct images of the various parts of the lungs.
- Medical ultrasonography is a form of ultrasound technology which can be used to diagnose obstructive lung diseases. Ultrasound uses sound waves with a frequency of about 20 kilohertz which are not audible to humans but may also be used at lower frequencies of between 2 and 18 kilohertz. This method involves producing sound waves which bounce back on body organs to generate an image of the body part.
The last two methods are not commonly used but can be useful in a situation where all other methods have failed or are not suitable for use.