It affects a part of your body called the pleura. When you are healthy, you never notice your pleura at work. But if your pleura has a problem, you will feel it. The pleura is a thin layer of tissue that wraps your lungs. They fit snugly within your chest, which is lined with another thin layer of pleura. These layers keep your bare lungs from rubbing against the wall of your chest cavity every time you breathe in. There’s a bit of fluid within the narrow space between the two layers of pleura to keep everything moving smoothly.

Allergies are an abnormal response of the immune system. It is an acquired potential for developing adverse reactions that are immunologically mediated to the substances that are mostly harmless to us. This substance (pollen, mould, animal dander for example)is called an allergen. Atopy is the inheritance tendency to develop allergies.

Polysomnography, also called a sleep study, is a comprehensive test used to diagnose sleep disorders. Polysomnography records your brain waves, the oxygen level in your blood, heart rate and breathing, as well as eye and leg movements during the study. Polysomnography may be done at a sleep disorders unit within a hospital or at a sleep center. While it's typically performed at night, polysomnography is occasionally done during the day to accommodate shift workers who habitually sleep during the day.

Bronchoalveolar lavage also known as BAL or bronchoalveolar washing, is a minimally invasive procedure and a diagnostic tool of the lower respiratory system in which a flexible bronchoscope is passed through the mouth or nose into a sub-segment of the lung, with instillation of sterile normal saline into a subsegment of the lung, followed by suction and collection of the instillation for analysis 1). Analysis of the bronchoalveolar lavage cytology reflects the cellular composition within the alveoli making BAL part of diagnostic workup for suspected lung diseases. Bronchoalveolar lavage serves predominantly as a diagnostic tool for the evaluation of lower respiratory tract pathology and in some uncommon conditions, it also has therapeutic utility .