Disorder Profiles for NEET

1. Asthma

• Cause: Allergic or inflammatory response → bronchospasm, mucosal oedema, excess mucus → airway narrowing
• Pathology: Reversible narrowing of bronchi and bronchioles
• Key symptom: Wheezing, breathlessness (especially on expiration), cough
• Lung volume changes: Increased RV and FRC (air trapping); decreased FEV1/FVC ratio
• Clinical note: Reversible with bronchodilators (beta-2 agonists, corticosteroids)

2. Emphysema

• Cause: Chronic irritants (most commonly cigarette smoke) → inflammation → protease release → alveolar wall destruction
• Pathology: Irreversible destruction of alveolar walls → loss of elastic recoil → air trapping
• Key symptoms: Progressive dyspnoea (breathlessness), barrel chest, cough (less mucus than chronic bronchitis)
• Lung volume changes: ↑RV, ↑TLC, ↑FRC, ↓VC, ↓FEV1/FVC
• Clinical note: Cannot be reversed; managed with bronchodilators and O2 therapy

3. Silicosis

• Cause: Chronic inhalation of silica (SiO2) dust — mining, stone cutting, sandblasting
• Pathology: Silica particles activate macrophages → fibrosis (scar tissue) in lung parenchyma
• Key symptoms: Progressive dyspnoea, reduced lung compliance (stiff lungs), reduced gas exchange
• Lung volume changes: ↓TLC, ↓VC (restrictive pattern), RV may be normal initially
• Clinical note: Preventable with dust masks; irreversible once fibrosis develops

4. Asbestosis

• Cause: Long-term inhalation of asbestos fibres (construction, shipbuilding, insulation)
• Pathology: Fibrosis of lung parenchyma + pleural plaques
• Key symptoms: Progressive dyspnoea, dry cough, reduced lung compliance
• Special risk: Significantly increased risk of mesothelioma (pleural cancer) and lung cancer
• Lung volume changes: Restrictive pattern (↓TLC, ↓VC)

Comparison Table