A 55-year-old with 30 pack-years presents with chronic dyspnea and wheezing. PFTs show FEV1/FVC < 0.7. After albuterol, FEV1 improves by 8%.
Asthma or COPD?
The Core Split
These two diseases both cause airflow obstruction and wheezing. That's where the similarity ends. Flip between tabs · notice how different the stories are.
⚡ ASTHMA
🫁 COPD
Clinical Images
📷 PFTs: obstructive vs restrictive patterns · tap to expand
Who Gets It
Young. Often childhood onset. Atopic history · eczema, allergic rhinitis, food allergies. Family history of asthma. The kid who couldn't run the mile in gym class.
What's Happening
Eosinophilic inflammation → bronchial hyperreactivity → airway smooth muscle spasm → reversible obstruction. The airways are twitchy, not destroyed.
The Key Feature
REVERSIBLE. Give albuterol → FEV1 jumps ≥12% AND ≥200mL. The airways open back up because the walls are still intact. They're just spasming.
Triggers
Allergens (dust, pollen, dander)
Exercise (especially cold air)
Infections (viral URI)
NSAIDs (aspirin-exacerbated respiratory disease)
Emotional stress
Treatment Backbone
Inhaled corticosteroids (ICS) are the controller. SABA for rescue. Step up with LABA + ICS combo. The goal is no symptoms · and that's actually achievable.
Who Gets It
Older smoker. Usually 40+ with significant smoking history. The guy who smoked a pack a day for 30 years and now can't climb stairs.
Chronic bronchitis · "blue bloater." Overweight, cyanotic, productive cough ≥3 months/year for 2+ years. Mucus glands take over
Treatment Backbone
LAMA (tiotropium) is the first-line controller. Add LABA. ICS only added for frequent exacerbations (≥2/year). Smoking cessation is the ONLY thing proven to slow decline. O2 if PaO2 ≤55.
Feature-by-Feature
One screen. All the differences. Lead with what's DIFFERENT, not what's shared.
⚡ Asthma
🫁 COPD
Age
Young (childhood-20s)
>40, smoker
Reversibility
Yes (≥12% + 200mL)
No (<12%)
Inflammation
Eosinophils
Neutrophils
FEV1/FVC
Normal between attacks
<0.7 always
Symptoms
Episodic, triggered
Persistent, progressive
CXR
Usually normal
Hyperinflation, flat diaphragms
1st-line controller
ICS
LAMA
Prognosis
Can achieve full control
Progressive decline
Key history
Atopy, allergies, eczema
Pack-years, occupational exposure
DLCO
Normal
↓↓ (destroyed alveoli)
The Villains
Three airway disorders. Each one presents differently and demands a different fight. Tap a card to flip it.
Asthma Airway
Emphysema
Barrel Chest
Spirometry
⚡
Asthma
Reversible. Eosinophilic. Twitchy.
tap to flip
Asthma
Who: Young, atopic. Eczema, allergies, family history.
Subtypes:Pink puffer (emphysema, low BMI, hyperinflated) vs Blue bloater (chronic bronchitis, hypercapnic, edematous).
Rx: LAMA first. Add LABA. ICS only if ≥2 exacerbations/year. O2 if PaO2 ≤55. Smoking cessation = only proven mortality benefit.
🌀
ACOS
Asthma-COPD Overlap Syndrome
tap to flip
ACOS (Overlap)
Who: Older patient with asthma history who smoked, OR young smoker with partially reversible obstruction.
Spirometry: FEV1/FVC <0.7 (like COPD) but also shows ≥12% reversibility (like asthma). Both criteria met.
Inflammation: Mixed eosinophilic + neutrophilic. The two diseases collide.
Board trap: clinical medicine test clean patterns. Only call ACOS when they explicitly give BOTH disease features. If it looks like COPD, call COPD. If it looks like asthma, call asthma.
Rx: ICS + LABA (treat both components). More exacerbations, worse outcomes than either alone.
PFT Flow-Volume Loops
The shape of the expiratory limb tells you the diagnosis. Click a pattern to examine it.
Board Pearl
1FEV1 / FVC < 0.7 = obstructive (asthma or COPD).
2FVC reduced + FEV1 / FVC normal (> 0.7) = restrictive. Confirm with TLC < 80% predicted.
3Scooped expiratory limb = obstructive. Small but normal-shaped loop = restrictive.
4FEF 25 to 75 drops first in early small-airway disease (asthma, early COPD), before the FEV1 / FVC ratio crosses below 0.7.
clinical medicine shortcut: scooped = obstructive. Small = restrictive. Normal = neither. Click each button for the full breakdown.
Normal
FEV1 / FVC> 0.70
FVCNormal
TLC80 to 120% predicted
ShapeRapid rise to PEF, then linear decline
The reference shape. Airways open fully, peak flow is high, exhalation is unrestricted. Memorize this first. Everything else is a deviation from it.
Obstructive (Asthma / COPD)
FEV1 / FVC< 0.70 (diagnostic cutoff)
FVCNormal or slightly reduced
TLCNormal or increased (air trapping)
Key shapeScooped / concave expiratory limb
Asthma vs COPDAsthma: reversible post-bronchodilator
The concave scoop = small airways collapsing mid-exhalation, cutting off flow before the lungs are empty. FEF 25 to 75% is the most sensitive marker. In asthma, the curve normalizes with bronchodilator. In COPD, it does not.
Restrictive (Fibrosis / Sarcoid)
FEV1 / FVCNormal or elevated (> 0.70)
FVCReduced
TLC< 80% predicted (gold standard)
ShapeNormal proportions, compressed loop
Stiff lungs cannot expand, so TLC and FVC are both reduced. But once you start exhaling, airway patency is intact: FEV1/FVC stays normal or elevated. TLC below 80% predicted is the gold standard diagnostic criterion.
Memory Hooks
🔑
Reversibility is the whole game. Tap for the hook →
Asthma is a rubber band · stretches and snaps back. COPD is a broken rubber band · once it snaps, you can't unsnap it. Albuterol tests which one you're holding.
🔑
First-line controllers are backwards. Tap →
Asthma = ICS (the Inflammation is the problem · calm it down). COPD = LAMA (the Lungs are structurally locked · force them open). ICS doesn't fix broken walls. LAMA doesn't fix twitchy muscles. Match the drug to the damage.
🔑
The cell tells you the disease. Tap →
Eosinophils = Early onset, Episodic → Asthma. Neutrophils = Never going back, Nicotine damage → COPD. The inflammatory cell IS the diagnosis.
🔑
Pink puffer vs blue bloater. Tap →
Pink puffer (emphysema): hyperventilates to compensate → stays pink but exhausted. Thin because all that breathing burns calories. Blue bloater (chronic bronchitis): stops trying to compensate → CO2 retention → cyanosis. Overweight because NOT burning extra calories breathing. The body's coping strategy determines the phenotype.
The Algorithm
Board vignette drops. Patient is wheezing. Walk through it.
Step 1: How old is the patient?
Child / young adult (<40)
Older adult (>40)
Elimination Rounds
Five patients walk in wheezing. Don't give them the wrong inhaler.
clinical questions
Read every explanation, not just the correct answer.
Q1 of 8
A 45-year-old with a 25 pack-year history presents with FEV1/FVC of 0.64. After albuterol, FEV1 improves by 9%. What is the most appropriate first-line controller medication?
A. Inhaled corticosteroid (fluticasone)
B. Long-acting muscarinic antagonist (tiotropium)
C. Short-acting beta-agonist PRN only
D. Oral prednisone taper
Q2 of 8
Which PFT finding BEST distinguishes asthma from COPD in a patient with FEV1/FVC of 0.65?
A. Decreased FEV1
B. Decreased FVC
C. Bronchodilator reversibility (FEV1 improves ≥12% AND ≥200mL)
D. Decreased DLCO
Q3 of 8
A 28-year-old with childhood eczema presents with episodic wheezing worsened by cat exposure. Baseline spirometry is normal. What test would confirm airway hyperreactivity?
A. High-resolution CT chest
B. Methacholine challenge test
C. Serum eosinophil count alone
D. Exhaled nitric oxide (FeNO)
Q4 of 8
A 32-year-old non-smoker presents with lower-lobe panacinar emphysema on CT. He has chronic liver disease. What should be tested first?
A. Sputum culture for TB
B. Sweat chloride test for cystic fibrosis
C. Alpha-1 antitrypsin level and Pi genotyping
D. Pulmonary function tests only
Q5 of 8
A COPD patient has had 3 exacerbations in the past year despite LAMA + LABA. Blood eosinophil count is 420 cells/mcL. What should be added?
A. Roflumilast (PDE4 inhibitor)
B. Inhaled corticosteroid (ICS)
C. Theophylline
D. Oral azithromycin prophylaxis
Q6 of 8
A 70-year-old with COPD on home oxygen has SpO2 of 96%. He becomes somnolent and confused. His SpO2 is now 99%. What is the most likely mechanism?
A. Paradoxical bronchospasm from high-flow oxygen
B. Over-oxygenation blunted hypoxic drive, causing CO2 retention
C. Pulmonary embolism causing hypercapnia
D. Hypoxic vasoconstriction released, causing shunting
Q7 of 8
A child uses their albuterol 4 days per week and wakes up coughing twice per month. What asthma step is appropriate and what drug should be started?
A. Step 1 (intermittent) · SABA PRN only
B. Step 2 (mild persistent) · low-dose ICS as daily controller
C. Step 3 (moderate persistent) · low-dose ICS plus LABA
D. Step 4 (severe persistent) · medium-dose ICS plus LABA
Q8 of 8
Which is the ONLY intervention proven to reduce mortality in COPD patients with PaO2 at or below 55 mmHg?
A. Tiotropium (LAMA)
B. Pulmonary rehabilitation
C. Long-term supplemental oxygen (at least 15 h/day)
Original clinical vignettes. Shuffled, never-repeat, full explanations for every choice.
Medically reviewed by Kaitlyn Cocuzzo, MD and Fatima Ali, DO · Last reviewed June 2026
Bone Wizardry is an independent educational resource for visual learning in the medical sciences. It is not affiliated with, endorsed by, or sponsored by any licensing or examination board, contains no real or recalled examination questions, and does not guarantee any educational or examination outcome.
