Asthma & COPD for NEET PG — Complete Guide 2026

Version 1.0 — Published February 2026

Asthma and COPD are the two major obstructive airway diseases in NEET PG — and while both feature airflow obstruction on spirometry, they differ fundamentally in pathology, reversibility, age of onset, and treatment. The student who masters the GINA and GOLD frameworks, spirometry interpretation, and acute exacerbation management has covered 2–3 marks across medicine and pharmacology. Pair this guide with daily MCQ practice on the Medicine subject hub and cross-reference the high-yield medicine topics overview for adjacent pulmonology topics.

Asthma pathophysiology

Asthma is a chronic inflammatory disease of the airways characterized by reversible airflow obstruction, airway hyperresponsiveness, and episodic wheezing.

Core pathologic features:

1. Airway inflammation — dominated by Type 2 (Th2) cytokines: IL-4, IL-5, IL-13
2. Bronchoconstriction — smooth muscle contraction mediated by histamine, leukotrienes, acetylcholine
3. Mucus hypersecretion — goblet cell hyperplasia and Curschmann spirals in sputum
4. Airway remodeling — subepithelial fibrosis, smooth muscle hypertrophy, angiogenesis (chronic disease)

Key cells:

• Mast cells — IgE-mediated degranulation releases histamine, leukotrienes (early-phase response)
• Eosinophils — release major basic protein, eosinophil cationic protein (late-phase response, marker in sputum and blood)
• Th2 lymphocytes — orchestrate inflammation via IL-4/5/13

Histologic hallmarks (sputum and BAL):

• Charcot-Leyden crystals — eosinophil-derived (lysophospholipase)
• Curschmann spirals — mucus casts of small airways
• Creola bodies — shed respiratory epithelial cells

Triggers:

• Allergic: dust mite, pollen, pet dander, fungal spores (atopic individuals)
• Non-allergic: cold air, exercise, aspirin, beta-blockers, respiratory infections (viral), occupational (isocyanates, flour)
• Samter triad — aspirin-exacerbated respiratory disease: asthma + nasal polyps + aspirin sensitivity

Atopic march: atopic dermatitis (infancy) → food allergy → allergic rhinitis → asthma (childhood).

GINA severity classification and stepwise management

Asthma severity is classified by the level of treatment required to achieve and maintain control — with the Global Initiative for Asthma (GINA) 2023 framework as the NEET PG standard.

Severity categories (retrospective, based on treatment step):

• Mild asthma — well-controlled on GINA Step 1 or 2 (as-needed low-dose ICS-formoterol)
• Moderate asthma — well-controlled on Step 3 or 4 (low-medium dose ICS-LABA)
• Severe asthma — requires Step 5 (high-dose ICS-LABA + add-ons: tiotropium, biologics, OCS)

GINA 2023 stepwise management (adults/adolescents ≥12 years):

Key 2023 update: GINA eliminated SABA-only therapy (even at Step 1) due to rebound bronchospasm, increased inflammation, and mortality with SABA over-reliance (>=3 canisters per year = increased death risk).

MART (Maintenance And Reliever Therapy): ICS-formoterol used both as scheduled controller and as-needed reliever. Reduces exacerbations by 30% vs SABA reliever.

Achieving asthma control (GINA):

• Daytime symptoms ≤2 times/week
• No nocturnal awakening
• SABA use ≤2 times/week (for non-MART regimens)
• No limitation of activity

Step-down: After 3 months of good control, reduce to the lowest effective step. Never discontinue ICS entirely — loss of control risk.

Inhaler devices

Inhaler devices are the delivery systems for inhaled medications, and device selection based on patient capability is a practical NEET PG topic.

Device selection rules:

• Acute exacerbation — nebulizer or pMDI + spacer (patient may be unable to generate inspiratory flow for DPI)
• Young children (<5 yr) — pMDI + spacer + face mask
• Elderly with arthritis — Respimat (low actuation force)
• Poor coordination — spacer or DPI

Most common NEET PG error: Using a DPI during severe acute asthma — these require inspiratory flow patients cannot generate when severely obstructed.

COPD — definition and diagnosis

COPD is a heterogeneous lung condition characterized by persistent respiratory symptoms (dyspnea, cough, sputum) and airflow limitation due to airway and/or alveolar abnormalities from significant exposure to noxious particles (GOLD 2024).

Diagnostic criteria:

1. Exposure: Tobacco smoke (most common worldwide), biomass fuel (major cause in Indian women), occupational dust/chemicals
2. Symptoms: Dyspnea (progressive, persistent), chronic cough, sputum production, wheezing
3. Spirometry: Post-bronchodilator FEV1/FVC <0.70 (required for diagnosis)

Risk factors:

• Smoking (dose-dependent, pack-years)
• Indoor biomass fuel (wood, cow dung — major in rural India)
• Occupational exposure (coal, silica, cotton dust — byssinosis)
• Alpha-1 antitrypsin deficiency (young onset, basal emphysema, consider if COPD in non-smoker <45 years)
• Childhood respiratory infections

GOLD 2024 classification of airflow limitation severity (based on FEV1 % predicted, post-bronchodilator):

GOLD ABE classification (2023+, used for treatment):

(Previous GOLD used ABCD — simplified to ABE because exacerbation history matters more than symptom burden for choosing therapy.)

Emphysema vs chronic bronchitis

Emphysema and chronic bronchitis are the two pathologic phenotypes of COPD, traditionally distinguished as "pink puffer" and "blue bloater" — most patients have overlapping features.

Types of emphysema:

• Centriacinar (centrilobular) — most common, apical, smoking-related, destroys central acinus
• Panacinar — basal, alpha-1 antitrypsin deficiency, destroys entire acinus
• Paraseptal — subpleural, spontaneous pneumothorax risk in young thin males
• Irregular — scar-related (post-TB, sarcoidosis)

Reid index: Ratio of gland layer thickness to total bronchial wall thickness. Normal <0.4; chronic bronchitis >0.4.

Spirometry interpretation

Spirometry is the pulmonary function test measuring airflow during forced expiration — the single most tested investigation in NEET PG pulmonology.

Key values:

• FVC (forced vital capacity): Total volume exhaled from total lung capacity to residual volume
• FEV1 (forced expiratory volume in 1 second): Volume exhaled in first second
• FEV1/FVC ratio: The discriminator between obstructive and restrictive disease

Pattern interpretation:

Bronchodilator reversibility:

• Significant reversibility — FEV1 increase of >=12% AND >=200 mL after short-acting bronchodilator
• Characteristic of asthma (but 15–30% of COPD patients also show reversibility)
• Absence of reversibility does NOT rule out asthma

Flow-volume loops:

• Asthma: "Coved" expiratory limb from small airway collapse
• COPD: Same coved pattern, typically more severe
• Fixed upper airway obstruction (tracheal stenosis): Flattened inspiratory AND expiratory limbs
• Variable extrathoracic obstruction (vocal cord paralysis): Flattened inspiratory limb only
• Variable intrathoracic obstruction (tracheomalacia): Flattened expiratory limb only

Other lung function measurements:

• TLC — increased in emphysema (hyperinflation); decreased in restrictive disease
• DLCO — decreased in emphysema, pulmonary fibrosis, PE; normal in chronic bronchitis, asthma
• Residual volume — increased in obstructive disease (air trapping)

Exacerbation management

Acute asthma exacerbation requires immediate stepped-up therapy with four principal interventions.

Severity grading:

• Mild-moderate: PEF >50%, can speak in sentences, HR <120, RR <30, SpO2 >90%
• Severe: PEF <50%, speaks in words, HR >120, RR >30, SpO2 88–90%
• Life-threatening: Silent chest, cyanosis, confusion, hypotension, bradycardia, SpO2 <88%, PEF <33%, PaCO2 rising (normal or high in severe attack is a RED FLAG — impending respiratory failure)

Management:

1. Oxygen — target SpO2 93–95% (not higher — risk of hyperoxemic hypercapnia in chronic respiratory disease)
2. SABA (salbutamol) — nebulizer 2.5–5 mg every 20 minutes x 3 doses, then hourly
3. Ipratropium — add-on in severe, 500 mcg with each SABA neb for first 3 doses
4. Systemic steroids — oral prednisolone 40–50 mg daily x 5 days (equivalent efficacy to IV), IV hydrocortisone 100 mg if unable to take oral
5. IV magnesium sulfate — 2 g over 20 minutes for severe exacerbation not responding
6. Non-invasive ventilation — consider if acidotic respiratory failure not improving
7. Intubation — silent chest, exhaustion, bradycardia, altered consciousness

Antibiotics: NOT routinely indicated for asthma exacerbation (most triggered by viral infection).

COPD exacerbation is defined as an acute worsening of respiratory symptoms requiring additional therapy — and is the leading cause of hospital admission among COPD patients.

Anthonisen criteria (bacterial vs viral trigger):

• Increased dyspnea
• Increased sputum volume
• Increased sputum purulence

Antibiotic indications (COPD exacerbation): All 3 cardinal symptoms, OR 2 with increased sputum purulence, OR mechanical ventilation required. First-line: amoxicillin-clavulanate, macrolide, or doxycycline. Pseudomonas cover (levofloxacin, piperacillin-tazobactam) if severe COPD / frequent exacerbations / prior Pseudomonas.

Most common pathogens: Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis; rhinovirus, influenza.

Non-invasive ventilation (NIV): First-line for hypercapnic respiratory failure (pH <7.35, PaCO2 >45). Reduces intubation rate by 58% and mortality by 46% in COPD exacerbation.

Long-term oxygen therapy in COPD

Long-term oxygen therapy (LTOT) is continuous home oxygen (>=15 hours/day) — the ONLY pharmacological intervention proven to reduce mortality in COPD.

Indications (must meet criteria on arterial blood gas at rest, room air, stable):

• Absolute: PaO2 <=55 mmHg OR SaO2 <=88%
• Relative: PaO2 55–60 mmHg with evidence of end-organ damage:
  • Pulmonary hypertension
  • Cor pulmonale (right heart failure)
  • Secondary polycythemia (hematocrit >55%)

Target: PaO2 >60 mmHg or SaO2 >90%. Flow typically 1–2 L/min via nasal cannula.

Mortality benefit:

• NOTT trial (1980): 19-hour/day oxygen reduced mortality vs 12-hour
• MRC trial (1981): Oxygen >=15 hr/day reduced mortality vs no oxygen
• Must be continuous to work — ambulatory oxygen alone does not reduce mortality

Contraindication: Continued smoking (fire risk) — smoking cessation is mandatory before LTOT prescription.

Pharmacologic management of stable COPD (GOLD 2024):

ICS considerations in COPD: Not first-line monotherapy. Combine with LABA only if frequent exacerbations and eosinophilic phenotype (>=300/microL). Increased risk of pneumonia.

Smoking cessation remains the single most impactful intervention — reduces rate of FEV1 decline from 62 to 31 mL/year (Lung Health Study).

Asthma vs COPD — the discriminating comparison

A direct comparison is consistently tested because NBE loves this distinction.

ACOS (Asthma-COPD Overlap Syndrome): Patient with persistent airflow limitation (like COPD) but significant reversibility and eosinophilic inflammation (like asthma). Features of both diseases. Treat with ICS-LABA-LAMA triple therapy.

Sources and references

1. Global Initiative for Asthma (GINA) — 2023 Global Strategy for Asthma Management and Prevention — the international standard for asthma classification and management.
2. Global Initiative for Chronic Obstructive Lung Disease (GOLD) — 2024 Global Strategy for Prevention, Diagnosis and Management of COPD.
3. Harrison's Principles of Internal Medicine, 21st Edition (Loscalzo et al., 2022) — Chapters on Asthma and COPD.
4. Fishman's Pulmonary Diseases and Disorders, 5th Edition (Grippi et al., 2015) — detailed pathophysiology of obstructive lung disease.
5. Nocturnal Oxygen Therapy Trial Group — Annals of Internal Medicine 1980; 93:391-398 — landmark evidence for LTOT mortality benefit in COPD.
6. API Textbook of Medicine, 11th Edition (Munjal et al., 2019) — Indian-context epidemiology including biomass fuel exposure.

Frequently asked questions

How many asthma/COPD questions appear in NEET PG?

Obstructive airway disease contributes 2-3 direct questions per NEET PG paper across medicine, pharmacology, and pediatrics. Spirometry interpretation (FEV1/FVC ratio), GINA stepwise management, and COPD exacerbation treatment are the three most frequently tested subtopics based on 2019-2025 pattern analysis.

What is the key spirometry finding in obstructive disease?

Post-bronchodilator FEV1/FVC ratio less than 0.70 (or less than lower limit of normal) defines airflow obstruction in both asthma and COPD. In asthma, reversibility is demonstrated by FEV1 improvement of 12 percent and 200 mL after bronchodilator. In COPD, airflow limitation is persistent and not fully reversible. TLC is increased in emphysema; DLCO is reduced.

How is asthma severity classified by GINA?

GINA classifies asthma severity retrospectively based on the step of treatment required for control. Mild asthma is well-controlled on Steps 1-2 (as-needed ICS-formoterol). Moderate asthma requires Step 3-4 (low-medium dose ICS-LABA). Severe asthma requires Step 5 (high-dose ICS-LABA plus add-ons like tiotropium, biologics, or oral steroids).

What is the first-line controller in GINA 2023?

As-needed low-dose ICS-formoterol is first-line for mild asthma across all adults and adolescents (Step 1-2). GINA eliminated SABA-only therapy because of rebound bronchospasm and mortality risk. For persistent symptoms (Step 3), add regular low-dose ICS-formoterol as maintenance plus as-needed reliever (MART regimen).

What is the GOLD ABCD classification for COPD?

GOLD 2024 uses ABE classification (simplified from ABCD in 2023): Group A is low symptoms (CAT less than 10, mMRC 0-1) with 0-1 moderate exacerbations. Group B is high symptoms with 0-1 exacerbations. Group E is high exacerbation history (2 or more moderate OR 1 severe requiring hospitalization) regardless of symptoms. Management is tailored to groups.

How do I differentiate emphysema from chronic bronchitis?

Emphysema is the pink puffer: thin, dyspnea-predominant, hyperinflated chest, diminished breath sounds, increased TLC, reduced DLCO, pursed-lip breathing. Chronic bronchitis is the blue bloater: overweight, cough and sputum for 3 months in 2 consecutive years, cyanosis, cor pulmonale, normal TLC, normal DLCO, productive cough. Most COPD patients have mixed phenotypes.

When is long-term oxygen therapy indicated in COPD?

Long-term oxygen therapy (LTOT, greater than 15 hours per day) is indicated when PaO2 is less than or equal to 55 mmHg or SaO2 less than or equal to 88 percent at rest. LTOT is also indicated when PaO2 is 55-60 mmHg with evidence of pulmonary hypertension, cor pulmonale, or polycythemia (hematocrit over 55 percent). LTOT is the only intervention proven to reduce mortality in COPD alongside smoking cessation.

What is the management of acute asthma exacerbation?

Treat with oxygen to target SpO2 93-95 percent, nebulized short-acting beta-2 agonist (salbutamol 2.5-5 mg every 20 minutes x 3 doses), systemic corticosteroids (oral prednisolone 40-50 mg daily x 5 days or IV hydrocortisone), ipratropium nebulizer if severe, and IV magnesium sulfate 2 g for severe exacerbations not responding to initial therapy. ICU admission if impending respiratory failure.

Which vaccines are recommended in COPD?

Annual influenza vaccine, 23-valent pneumococcal polysaccharide (PPSV23) once after age 65 (or earlier if at risk), 13-valent pneumococcal conjugate (PCV13) in sequence, Tdap booster, and Herpes zoster vaccine after age 50. These reduce COPD exacerbations and mortality. COVID-19 vaccine is also recommended. Smoking cessation remains the single highest-impact intervention.

What is the role of biologics in severe asthma?

Biologics target Type 2 inflammation in severe asthma uncontrolled on high-dose ICS-LABA. Anti-IgE (omalizumab) for allergic asthma with elevated IgE. Anti-IL-5 (mepolizumab, reslizumab) or anti-IL-5R (benralizumab) for eosinophilic asthma (blood eosinophils over 300). Anti-IL-4R-alpha (dupilumab) for both eosinophilic and Type 2 high asthma. Reduce exacerbations by 50-70 percent.

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Written by: NEETPGAI Editorial Team Reviewed by: Pending SME Review Last reviewed: February 2026

This article is reviewed by qualified medical professionals for clinical accuracy and exam relevance. For corrections or updates, contact the editorial team.