MBBS Year
1st Year
Subject
What Is Usually Asked
Airway resistance, lung function tests, spirometry
ReferenceAll Years (1st-Final)All UniversitiesAsthma
Asthma: Notes, PPT and PYQs for MBBS
Asthma (bronchial asthma) is a chronic inflammatory disease of the airways that causes recurrent wheeze, breathlessness, chest tightness and cough, with variable and often reversible airflow limitation. It is examined in Physiology in 1st Year, Pathology and Pharmacology in 2nd Year, and General Medicine and Paediatrics in Final Year.
SME-reviewed. Updated 2026.
Open in GeckoMed for PPT slides and notes.Quick Summary: What You Need to Know for University Exams
- Asthma is a heterogeneous disease with chronic airway inflammation and variable expiratory airflow limitation.
- Symptoms vary over time and are often worse at night or early morning.
- The main mechanism is Th2-driven inflammation with mast cells, eosinophils, IgE and airway hyperresponsiveness.
- Spirometry with bronchodilator reversibility supports the diagnosis.
- Inhaled corticosteroids (ICS) are the cornerstone of long-term control; current Global Initiative for Asthma (GINA) guidance does not recommend reliever-only treatment with a short-acting beta-agonist (SABA) for adults and adolescents.
- A "silent chest" in an acute attack is a life-threatening sign.
- Inhaler technique and adherence are central to good control.
Asthma Across MBBS Subjects
| MBBS Year | Subject | What Is Usually Asked |
|---|---|---|
| 1st Year | Physiology | Airway resistance, lung function tests, spirometry |
| 2nd Year | Pathology | Pathogenesis, morphology, Curschmann spirals, Charcot-Leyden crystals |
| 2nd Year | Pharmacology | Classification of drugs for bronchial asthma, salbutamol, corticosteroids, montelukast, theophylline |
| Final Year | General Medicine | Diagnosis, stepwise management, acute severe asthma |
| Final Year | Paediatrics | Childhood asthma and wheezing |
MBBS Year
2nd Year
Subject
What Is Usually Asked
Pathogenesis, morphology, Curschmann spirals, Charcot-Leyden crystals
MBBS Year
2nd Year
Subject
What Is Usually Asked
Classification of drugs for bronchial asthma, salbutamol, corticosteroids, montelukast, theophylline
MBBS Year
Final Year
Subject
What Is Usually Asked
Diagnosis, stepwise management, acute severe asthma
MBBS Year
Final Year
Subject
What Is Usually Asked
Childhood asthma and wheezing
Definition and Classification
Definition (GINA): Asthma is a heterogeneous disease, usually characterised by chronic airway inflammation. It is defined by a history of respiratory symptoms such as wheeze, shortness of breath, chest tightness and cough that vary over time and in intensity, together with variable expiratory airflow limitation.
Types (Phenotypes)
| Type | Key Features |
|---|---|
| Allergic (extrinsic) asthma | Often begins in childhood; associated with atopy, allergic rhinitis, eczema and raised IgE |
| Non-allergic (intrinsic) asthma | Often adult onset; no evident allergy |
| Exercise-induced bronchoconstriction | Symptoms triggered by exercise |
| Occupational asthma | Caused by agents at work |
| Aspirin-exacerbated respiratory disease | Asthma, aspirin or NSAID sensitivity and nasal polyps (Samter's triad) |
| Cough-variant asthma | Chronic cough as the main symptom |
Type
Allergic (extrinsic) asthma
Key Features
Often begins in childhood; associated with atopy, allergic rhinitis, eczema and raised IgE
Type
Non-allergic (intrinsic) asthma
Key Features
Often adult onset; no evident allergy
Type
Exercise-induced bronchoconstriction
Key Features
Symptoms triggered by exercise
Type
Occupational asthma
Key Features
Caused by agents at work
Type
Aspirin-exacerbated respiratory disease
Key Features
Asthma, aspirin or NSAID sensitivity and nasal polyps (Samter's triad)
Type
Cough-variant asthma
Key Features
Chronic cough as the main symptom
Asthma Versus COPD
| Feature | Asthma | COPD |
|---|---|---|
| Age at onset | Often childhood or young adulthood | Usually after 40 years |
| Smoking history | Not essential | Usually significant |
| Symptoms | Variable, episodic | Persistent, slowly progressive |
| Reversibility | Marked reversibility with bronchodilator | Limited reversibility |
| Main inflammatory cells | Eosinophils, mast cells, Th2 cells | Neutrophils, macrophages, CD8 cells |
Feature
Age at onset
Asthma
Often childhood or young adulthood
COPD
Usually after 40 years
Feature
Smoking history
Asthma
Not essential
COPD
Usually significant
Feature
Symptoms
Asthma
Variable, episodic
COPD
Persistent, slowly progressive
Feature
Reversibility
Asthma
Marked reversibility with bronchodilator
COPD
Limited reversibility
Feature
Main inflammatory cells
Asthma
Eosinophils, mast cells, Th2 cells
COPD
Neutrophils, macrophages, CD8 cells
Aetiology (Triggers and Risk Factors)
Risk factors:
- Family history of asthma or atopy
- Personal atopy (allergic rhinitis, eczema)
- Exposure to tobacco smoke, including in pregnancy and childhood
- Obesity
- Occupational exposures
Common triggers:
| Trigger Type | Examples |
|---|---|
| Allergens | House dust mite, pollen, animal dander, cockroach, moulds |
| Infections | Viral respiratory infections |
| Irritants | Tobacco smoke, air pollution, strong odours |
| Physical | Exercise, cold air |
| Drugs | Aspirin and NSAIDs in sensitive people, non-selective beta-blockers |
| Others | Emotional stress, gastro-oesophageal reflux |
Trigger Type
Allergens
Examples
House dust mite, pollen, animal dander, cockroach, moulds
Trigger Type
Infections
Examples
Viral respiratory infections
Trigger Type
Irritants
Examples
Tobacco smoke, air pollution, strong odours
Trigger Type
Physical
Examples
Exercise, cold air
Trigger Type
Drugs
Examples
Aspirin and NSAIDs in sensitive people, non-selective beta-blockers
Trigger Type
Others
Examples
Emotional stress, gastro-oesophageal reflux
Pathophysiology
Immunological Mechanism (Flowchart)
- Genetic predisposition and allergen exposure
- Dendritic cells present allergen to Th2 cells
- Th2 cells release IL-4 (IgE production), IL-5 (eosinophil activation) and IL-13 (mucus production and hyperresponsiveness)
- IgE binds to mast cells; re-exposure to allergen causes mast cell degranulation
- Early phase: histamine, leukotrienes and prostaglandins cause bronchoconstriction, oedema and mucus secretion within minutes
- Late phase: eosinophils and other cells cause sustained inflammation hours later
- Repeated inflammation leads to airway remodelling
Airway Remodelling
- Thickening of the basement membrane (subepithelial fibrosis)
- Smooth muscle hypertrophy and hyperplasia
- Goblet cell hyperplasia and submucosal gland enlargement
- Increased vascularity
Pathology Findings
| Finding | Description |
|---|---|
| Curschmann spirals | Spiral mucus plugs from small airways |
| Charcot-Leyden crystals | Crystals formed from eosinophil proteins |
| Creola bodies | Clusters of shed epithelial cells |
| Lungs in fatal asthma | Overinflated, with mucus plugs in bronchi |
Finding
Curschmann spirals
Description
Spiral mucus plugs from small airways
Finding
Charcot-Leyden crystals
Description
Crystals formed from eosinophil proteins
Finding
Creola bodies
Description
Clusters of shed epithelial cells
Finding
Lungs in fatal asthma
Description
Overinflated, with mucus plugs in bronchi
(Examiner may ask you to draw the pathogenesis flowchart.)
Clinical Features
Symptoms:
- Episodic wheeze
- Breathlessness
- Chest tightness
- Cough, often worse at night or early morning
- Symptoms triggered by allergens, exercise, cold air or infections
Signs:
- Prolonged expiration
- Polyphonic expiratory wheeze
- Use of accessory muscles in severe attacks
- Examination may be normal between attacks
Assessing an Acute Attack
| Severity | Features |
|---|---|
| Mild to moderate | Talks in phrases, prefers sitting, not agitated, respiratory and heart rates raised |
| Severe | Talks in words, sits hunched forward, agitated, marked tachypnoea and tachycardia, accessory muscle use, low peak flow |
| Life-threatening | Drowsiness or confusion, silent chest, cyanosis, poor respiratory effort, exhaustion, bradycardia or hypotension |
Severity
Mild to moderate
Features
Talks in phrases, prefers sitting, not agitated, respiratory and heart rates raised
Severity
Severe
Features
Talks in words, sits hunched forward, agitated, marked tachypnoea and tachycardia, accessory muscle use, low peak flow
Severity
Life-threatening
Features
Drowsiness or confusion, silent chest, cyanosis, poor respiratory effort, exhaustion, bradycardia or hypotension
Pulsus paradoxus (an exaggerated fall in systolic pressure during inspiration) may be present in severe asthma.
Diagnosis
| Investigation | Findings or Purpose |
|---|---|
| Spirometry | Reduced FEV1/FVC ratio (obstructive pattern) |
| Bronchodilator reversibility | Improvement in FEV1 of more than 12% and more than 200 mL after a bronchodilator supports asthma |
| Peak expiratory flow (PEF) variability | Diurnal variation supports the diagnosis; useful for monitoring |
| Bronchial challenge test | Methacholine or histamine challenge shows airway hyperresponsiveness |
| Fractional exhaled nitric oxide (FeNO) | Marker of eosinophilic airway inflammation |
| Blood eosinophils and total IgE | Support allergic or eosinophilic asthma |
| Skin prick tests | Identify specific allergens |
| Chest X-ray | Usually normal; hyperinflation in acute attacks; excludes other causes and pneumothorax |
| Arterial blood gas | In acute severe asthma; a normal or rising PaCO2 in a breathless patient is a warning sign |
Investigation
Spirometry
Findings or Purpose
Reduced FEV1/FVC ratio (obstructive pattern)
Investigation
Bronchodilator reversibility
Findings or Purpose
Improvement in FEV1 of more than 12% and more than 200 mL after a bronchodilator supports asthma
Investigation
Peak expiratory flow (PEF) variability
Findings or Purpose
Diurnal variation supports the diagnosis; useful for monitoring
Investigation
Bronchial challenge test
Findings or Purpose
Methacholine or histamine challenge shows airway hyperresponsiveness
Investigation
Fractional exhaled nitric oxide (FeNO)
Findings or Purpose
Marker of eosinophilic airway inflammation
Investigation
Blood eosinophils and total IgE
Findings or Purpose
Support allergic or eosinophilic asthma
Investigation
Skin prick tests
Findings or Purpose
Identify specific allergens
Investigation
Chest X-ray
Findings or Purpose
Usually normal; hyperinflation in acute attacks; excludes other causes and pneumothorax
Investigation
Arterial blood gas
Findings or Purpose
In acute severe asthma; a normal or rising PaCO2 in a breathless patient is a warning sign
Management
Goals
- Good symptom control
- Prevention of attacks (exacerbations)
- Normal activity and lung function
- Minimal side effects of treatment
Drugs Used in Asthma
| Drug Class | Examples | Role |
|---|---|---|
| Short-acting beta-2 agonists (SABA) | Salbutamol, terbutaline | Quick relief of symptoms |
| Long-acting beta-2 agonists (LABA) | Salmeterol, formoterol | Add-on to ICS; never used alone in asthma |
| Inhaled corticosteroids (ICS) | Budesonide, beclomethasone, fluticasone | Main anti-inflammatory controller |
| ICS-formoterol combination | Budesonide-formoterol | Used as reliever and controller in current GINA tracks |
| Long-acting muscarinic antagonists (LAMA) | Tiotropium | Add-on in more severe asthma |
| Short-acting muscarinic antagonist | Ipratropium | Add-on in acute severe attacks |
| Leukotriene receptor antagonists | Montelukast | Add-on controller; useful in aspirin-exacerbated and exercise-induced asthma |
| Methylxanthines | Theophylline | Less used because of a narrow therapeutic index |
| Systemic corticosteroids | Prednisolone, hydrocortisone | Acute attacks and severe asthma |
| Biologics | Omalizumab (anti-IgE), mepolizumab (anti-IL-5), dupilumab (anti-IL-4 receptor) | Severe asthma under specialist care |
Drug Class
Short-acting beta-2 agonists (SABA)
Examples
Salbutamol, terbutaline
Role
Quick relief of symptoms
Drug Class
Long-acting beta-2 agonists (LABA)
Examples
Salmeterol, formoterol
Role
Add-on to ICS; never used alone in asthma
Drug Class
Inhaled corticosteroids (ICS)
Examples
Budesonide, beclomethasone, fluticasone
Role
Main anti-inflammatory controller
Drug Class
ICS-formoterol combination
Examples
Budesonide-formoterol
Role
Used as reliever and controller in current GINA tracks
Drug Class
Long-acting muscarinic antagonists (LAMA)
Examples
Tiotropium
Role
Add-on in more severe asthma
Drug Class
Short-acting muscarinic antagonist
Examples
Ipratropium
Role
Add-on in acute severe attacks
Drug Class
Leukotriene receptor antagonists
Examples
Montelukast
Role
Add-on controller; useful in aspirin-exacerbated and exercise-induced asthma
Drug Class
Methylxanthines
Examples
Theophylline
Role
Less used because of a narrow therapeutic index
Drug Class
Systemic corticosteroids
Examples
Prednisolone, hydrocortisone
Role
Acute attacks and severe asthma
Drug Class
Biologics
Examples
Omalizumab (anti-IgE), mepolizumab (anti-IL-5), dupilumab (anti-IL-4 receptor)
Role
Severe asthma under specialist care
Stepwise Treatment (Principles)
- Treatment is stepped up or down according to symptom control and risk of attacks.
- Current GINA guidance for adults and adolescents prefers low-dose ICS-formoterol as the reliever, with maintenance ICS added at higher steps.
- At higher steps, doses are increased and add-on drugs such as LAMA are used; severe asthma is referred for phenotyping and biologic therapy.
- Always check inhaler technique, adherence and triggers before stepping up.
Use your current textbook and the latest GINA report for step details, since recommendations are updated regularly.
Acute Severe Asthma (MBBS Level)
- Sit the patient up and give controlled oxygen to maintain adequate saturation
- Repeated inhaled or nebulised SABA
- Add nebulised ipratropium in severe attacks
- Systemic corticosteroids early (oral prednisolone or intravenous hydrocortisone)
- Intravenous magnesium sulphate in severe attacks not responding to initial treatment
- Monitor peak flow, oxygen saturation and blood gases
- Intensive care for life-threatening features, exhaustion or rising PaCO2
Non-Drug Measures
- Avoid known triggers and tobacco smoke
- Correct inhaler technique; spacers for children and during attacks
- Written asthma action plan
- Vaccination against influenza as advised
- Regular review
Complications
- Acute severe asthma (status asthmaticus) and respiratory failure
- Pneumothorax and pneumomediastinum
- Lobar collapse from mucus plugging
- Side effects of long-term steroids
- Fixed airflow obstruction from remodelling
- Death in poorly controlled or untreated severe attacks
Prognosis
Most people with asthma achieve good control with regular inhaled corticosteroid-containing treatment and correct inhaler use. Childhood asthma often improves with age, but may return later. Poor adherence, frequent attacks and previous life-threatening episodes predict worse outcomes.
Quick Viva Questions
Q: What is the main controller drug in asthma? A: Inhaled corticosteroids.
Q: Why should LABA never be used alone in asthma? A: LABA relieves bronchoconstriction but does not treat inflammation, and LABA monotherapy is associated with an increased risk of severe attacks.
Q: What are Curschmann spirals? A: Spiral-shaped mucus plugs from small airways, seen in the sputum of asthmatic patients.
Q: What is a "silent chest"? A: Very little air movement on auscultation in a severe attack; it is a life-threatening sign.
Q: What is Samter's triad? A: Asthma, aspirin sensitivity and nasal polyps.
Q: What spirometry finding supports reversibility? A: An increase in FEV1 of more than 12% and more than 200 mL after a bronchodilator.
How Asthma Appears in MBBS University Exams
Typical question styles (not attributed to specific papers or years):
- "Define bronchial asthma. Discuss the aetiology, pathogenesis, clinical features and management." (Long essay, General Medicine)
- "Classify drugs used in bronchial asthma. Write a note on inhaled corticosteroids." (Long essay, Pharmacology)
- "Discuss the management of acute severe asthma." (Short note, Medicine)
- "Describe the pathogenesis and morphology of bronchial asthma." (Short note, Pathology)
- "Write a short note on montelukast." (Short note, Pharmacology)
Frequently Asked Questions
What is the difference between asthma and COPD?
Asthma usually starts earlier, has variable symptoms and shows marked reversibility with bronchodilators. COPD usually follows long-term smoking, progresses slowly and shows limited reversibility.
Is salbutamol alone enough for asthma?
For adults and adolescents, current GINA guidance does not recommend treatment with a short-acting beta-agonist alone, because it does not treat airway inflammation. An inhaled corticosteroid-containing treatment is recommended.
Can I download the asthma PPT for my presentation?
Yes. Use the Download PPT button at the top of this page. The GeckoMed app also gives offline access to the slides and notes.
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