Pulmonary function tests
How lung volumes, airflow, gas transfer and blood gases are measured and what their patterns mean.
Checked against sourcesVerified 27 October 2026
Pulmonology
Diseases of the lungs, airways and pleura, and the control of breathing.
Introduction
Pulmonology is the study of the lungs, the airways and the pleura, and of how breathing is controlled. Lung disease is common, often silent until late, and closely tied to smoking, occupation and the heart, so it appears in almost every area of medicine.
This section starts with the one test that most lung diagnoses depend on, spirometry. It then moves through the diseases of the airways, the diseases of the lung tissue, respiratory failure and sleep-related breathing, the blood vessels of the lung, and finally lumps, fluid and air in the chest.
Every topic uses the same layout: a short summary, what you should be able to do afterwards, the mechanism, the clinical picture, tests, treatment and the traps. Cut-offs and drug choices are checked against named guidelines and shown with their source, because guidelines and countries sometimes differ.
How to study pulmonology
Read the pulmonary function tests topic first and return to it after each disease group. An obstructive, restrictive or mixed pattern narrows the list of possible diagnoses faster than almost any other single result.
For each disease, learn the mechanism before the facts: where in the airway or lung the process sits, what it does to airflow and gas exchange, and why the chest film, the spirometry and the blood gas look the way they do. Most signs and treatments follow from that.
Learn the emergencies as pathways: acute severe asthma, COPD exacerbation, tension pneumothorax, massive pulmonary embolism and acute respiratory failure. Practise saying the first three actions aloud, and use the check-yourself questions at the end of each topic a few days later.
Pulmonary embolism and pulmonary hypertension link to the cardiology section, and lung cancer, sarcoidosis and the occupational diseases link to several other systems, so follow the related links. Content here is for study and does not replace local protocols or a senior clinician's judgement.
Contents by part
The topics below are in teaching order. Each part builds on the one before it.
- Testing the lungs. Start with the test that defines the next topics: spirometry and what the patterns mean.
- Obstructive airway disease. The diseases in which air cannot get out freely: reversible narrowing, permanent narrowing and permanently widened, infected airways.
- Interstitial and occupational lung disease. Scarring and inflammation of the lung tissue itself, from unknown causes, from inhaled dusts and antigens, and from immune reactions.
- Respiratory failure and sleep-related breathing. When gas exchange fails, and the disorders in which breathing fails only during sleep.
- Pulmonary circulation. Disease of the lung vessels: the blockage that arrives suddenly and the pressure that rises slowly.
- Masses, pleura and air leaks. Lumps in the lung, cancer, fluid around the lung and air around the lung.
Topics
Arterial blood gas interpretation
Obtain and interpret arterial blood gases: sampling safely, normal values, oxygenation and the A-a gradient, and respiratory versus metabolic disorders.Checked against sourcesVerified 31 October 2026Chronic cough and haemoptysis
Causes, work-up and treatment of chronic cough and haemoptysis in adults, including red flags and life-threatening (massive) haemoptysis.Checked against sourcesVerified 31 October 2026Asthma
A chronic inflammatory airway disease causing wheeze and breathlessness, with reversible obstruction; modern stepwise management and acute care.Checked against sourcesVerified 27 October 2026Chronic obstructive pulmonary disease (COPD)
Chronic lung disease with persistent airflow obstruction: clinical features, diagnosis, staging, management and complications.Checked against sourcesVerified 27 October 2026Bronchiectasis
Permanent dilatation of the bronchi: causes, the cycle of inflammation and infection, diagnosis, management, complications, and low-resource care.Checked against sourcesVerified 27 October 2026
Alpha-1 antitrypsin deficiency
Genetics, emphysema and liver disease in alpha-1 antitrypsin deficiency; testing in early COPD and augmentation therapy.Checked against sourcesVerified 31 October 2026Smoking cessation and pulmonary rehabilitation
How to help a smoker quit, with brief advice, nicotine replacement, varenicline, bupropion, pulmonary rehabilitation and vaccination in chronic lung disease.Checked against sourcesVerified 31 October 2026Interstitial lung disease
A restrictive interstitial lung disease: how idiopathic pulmonary fibrosis and other causes are classified, diagnosed, and managed.Checked against sourcesVerified 27 October 2026Sarcoidosis
A multisystem granulomatous disease: how noncaseating granulomas form, how sarcoidosis presents by organ, and how it is diagnosed and treated.Checked against sourcesVerified 27 October 2026Pneumoconioses
Inhaled workplace dusts that scar the lungs: what silicosis, coal disease, asbestosis, beryllium disease, and byssinosis are, and how they differ.Checked against sourcesVerified 27 October 2026Hypersensitivity pneumonitis
Immune-mediated lung disease from inhaled antigens: farmer's, bird fancier's, humidifier and hot-tub lung; non-fibrotic and fibrotic forms.Checked against sourcesVerified 27 October 2026Eosinophilic pulmonary syndromes
Classification, diagnosis and treatment of pulmonary eosinophilia including ABPA, EGPA, eosinophilic pneumonia, and parasite- or drug-induced disease.Checked against sourcesVerified 27 October 2026Pulmonary vasculitis and diffuse alveolar haemorrhage
Pulmonary capillaritis and diffuse alveolar haemorrhage: GPA, anti-GBM disease and lupus, with causes, investigation, diagnosis and management.Checked against sourcesVerified 31 October 2026Hypoxaemia and respiratory failure
How hypoxaemia develops, how to read the blood gas and A-a gradient, and how to give oxygen and ventilatory support safely.Checked against sourcesVerified 27 October 2026Acute respiratory distress syndrome (ARDS)
Noncardiogenic acute hypoxaemic respiratory failure: definitions, Berlin and 2023 global criteria, imaging, ventilation and outcomes.Checked against sourcesVerified 27 October 2026Obstructive sleep apnoea and obesity hypoventilation
How airway collapse in sleep causes apnoea, how AHI severity is graded, how to diagnose and treat OSA, and how obesity hypoventilation differs.Checked against sourcesVerified 27 October 2026Oxygen therapy, non-invasive and invasive ventilation
Oxygen prescribing, high-flow nasal cannula, CPAP, BiPAP, intubation indications, ventilator settings and weaning in adult respiratory failure.Checked against sourcesVerified 31 October 2026Upper airway obstruction and aspiration
Upper airway obstruction and aspiration: recognition and management of stridor, foreign body, epiglottitis, vocal cord dysfunction, and aspiration.Checked against sourcesVerified 31 October 2026Lung transplantation and end-stage lung disease
Lung transplantation for end-stage lung disease: indications, referral timing, surgery, complications, and palliative care.Checked against sourcesVerified 31 October 2026Pulmonary embolism
Acute pulmonary embolism: risk factors, pathophysiology, diagnosis, risk stratification, treatment with doses, and complications.Checked against sourcesVerified 27 October 2026Pulmonary hypertension and cor pulmonale
How high pulmonary pressures arise, are classified, diagnosed and treated, and what they mean for the right heart and cor pulmonale.Checked against sourcesVerified 27 October 2026Solitary pulmonary nodule
A rounded opacity up to 3 cm surrounded by aerated lung: how to tell benign from malignant and what to do next.Checked against sourcesVerified 27 October 2026Lung cancer
Lung cancer from first suspicion to treatment by stage: risks, types, presentation, staging, molecular tests, and care in low-resource settings.Checked against sourcesVerified 27 October 2026Pleural effusion
How fluid accumulates in the pleural space, how transudates differ from exudates, and how to investigate, drain and treat effusions by cause.Checked against sourcesVerified 27 October 2026Pneumothorax
Air in the pleural space: types, how it presents, how imaging diagnoses it, and how current guidelines manage spontaneous, traumatic and tension cases.Checked against sourcesVerified 27 October 2026Pleural infection, empyema and lung abscess
How bacteria infect the pleural space and how aspiration abscesses form in the lung: stages, diagnosis, drainage, antibiotics, surgery, and outcomes.Checked against sourcesVerified 31 October 2026Mesothelioma and other pleural tumours
Malignant pleural mesothelioma and other pleural tumours: asbestos risk, effusion presentation, thoracoscopic diagnosis, histology, staging and treatment.Checked against sourcesVerified 31 October 2026Mediastinal masses and thymoma
Mediastinal masses by compartment, with thymoma: definition, imaging, biopsy, surgery, staging and management from ESMO, WHO and ITMIG.Checked against sourcesVerified 31 October 2026