1. Obstructive lung disease, defined as a decrease in the exhaled air flow caused by a narrowing or obstruction of the airways, such as with asthma, emphysema, and chronic bronchitis.

2. Restrictive lung disease, defined as a decrease in the total volume of air that the lungs are able to hold. Often this is due to a decrease in the elasticity or compliance of the lungs themselves or a problem in the expansion of the chest wall during inhalation.

3. A defect in the ability of the lung air sack tissue to promote the diffusion of oxygen into a person's blood. Most lung diseases actually involve a combination of these categories, such as emphysema, which is typified by both airflow obstruction and oxygenation problems.

Major lung diseases include:

• asthma
• BOOP
• chronic bronchitis
• COPD (chronic obstructive pulmonary disease)
• emphysema
• interstitial lung disease
• pulmonary fibrosis
• sarcoidosis

Other lung diseases include:

• asbestosis
• aspergilloma
• aspergillosis - acute invasive
• aspergillosis allergic
• atelectasis
• eosinophilic pneumonia
• lung cancer
• metastatic lung cancer
• necrotizing pneumonia
• pleural effusion
• pneumoconiosis
• pneumocystosis
• pneumonia
• pneumonia in immunodeficient patient
• pneumothorax
• pulmonary actinomycosis
• pulmonary alveolar proteinosis
• pulmonary anthrax
• pulmonary arteriovenous malformation
• pulmonary edema
• pulmonary embolus
• pulmonary histiocytosis X (eosinophilic granuloma)
• pulmonary hypertension
• pulmonary nocardiosis
• pulmonary tuberculosis
• pulmonary veno-occlusive disease
• rheumatoid lung disease

This is not a complete list of lung diseases.