Lung disease is any disease or disorder that occurs in the lungs or that causes the lungs to not work properly. There are three main types of lung disease:

1. Airway diseases -- These diseases affect the tubes (airways) that carry oxygen and other gases into and out of the lungs. These diseases cause a narrowing or blockage of the airways. They include asthma, emphysema, and chronic bronchitis. People with airway diseases sometimes describe the feeling as "trying to breathe out through a straw."
2. Lung tissue diseases -- These diseases affect the structure of the lung tissue. Scarring or inflammation of the tissue makes the lungs unable to expand fully ("restrictive lung disease"). It also makes the lungs less capable of taking up oxygen (oxygenation) and releasing carbon dioxide. Pulmonary fibrosis and sarcoidosis are examples of lung tissue diseases. People sometimes describe the feeling as "wearing a too-tight sweater or vest" that won't allow them to take a deep breath.
3. Pulmonary circulation diseases -- These diseases affect the blood vessels in the lungs. They are caused by clotting, scarring, or inflammation of the blood vessels. They affect the ability of the lungs to take up oxygen and to release carbon dioxide. These diseases may also affect heart function.

Most lung diseases actually involve a combination of these categories.

The most common lung diseases include:

• Asthma
• Chronic bronchitis
• COPD (chronic obstructive pulmonary disease)
• Emphysema
• Pulmonary fibrosis
• Sarcoidosis

Other lung diseases include:

• Asbestosis
• Aspergilloma
• Aspergillosis
• Aspergillosis - acute invasive
• 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