*Community-acquired Pneumonia- (CAP) refers to pneumonia (any of several lung diseases) contracted by a person with little contact with the healthcare system.
*Chronic Obstructive Pulmonary Disease- Chronic obstructive pulmonary disease (COPD) is a type of obstructive lung disease characterized by long-term breathing problems and poor airflow. The main symptoms include shortness of breath and cough with sputum production.
*Acute Exacerbation- Acute exacerbation of COPD also known as acute exacerbations of chronic bronchitis (AECB) is a sudden worsening of COPD symptoms (shortness of breath, quantity, and color of phlegm) that typically lasts for several days. It may be triggered by an infection with bacteria or viruses or by environmental pollutants.
*Atelactasis- the collapse or closure of a lung resulting in reduced or absent gas exchange. It may affect part or all of a lung. It is usually unilateral. It is a condition where the alveoli are deflated down to little or no volume, as distinct from pulmonary consolidation, in which they are filled with liquid.