What Is Pulmonology? A Guide

Pulmonology is the branch of medicine and biomedical science concerned with the lungs and the rest of the respiratory tract: how they develop, how they work, and what goes wrong with them. It is also called pneumology, respirology, or chest medicine depending on the country. It exists both as a clinical specialty, diagnosing and managing conditions such as asthma, chronic obstructive pulmonary disease (COPD), interstitial lung disease, and pulmonary hypertension, and as a research field spanning physiology, cell and molecular biology, genetics, epidemiology, and clinical trials. This guide explains what pulmonology covers and how it divides into subspecialties, then adds the research-administration layer generic overviews skip: who funds respiratory research, which methods and trial endpoints the field relies on, which societies and journals shape it, and how people train for it. Nothing here is medical advice; it describes a discipline, not how to treat or diagnose any individual.

What Is Pulmonology?

Pulmonology is the study of the respiratory system and its diseases. The system includes the upper airway, the trachea and bronchial tree, the alveoli where gas exchange occurs, the pulmonary blood vessels, the pleura surrounding the lungs, and the muscles and nerves that drive breathing. Its central physiological question is gas exchange: how oxygen gets into the blood, how carbon dioxide gets out, and how airflow, lung mechanics, circulation, and the brain’s control of breathing keep those processes matched to the body’s needs.

The word is used in two overlapping senses. In the clinical sense, a pulmonologist is a physician who diagnoses and manages respiratory disease. In the research sense, pulmonary science includes anyone studying lung biology or lung disease, including physiologists, cell biologists, immunologists, geneticists, bioengineers, epidemiologists, and nurses and respiratory therapists running clinical studies. A grant in this area may be led by someone who never sees patients.

How Pulmonology Relates to Neighboring Disciplines

Pulmonology overlaps heavily with its neighbors, and the boundaries are administrative as much as scientific. Lung injury and infection are inseparable from immunology, since the airway is one of the body’s largest surfaces facing the outside world. Breathing is controlled by brainstem circuits, which links the field to neurology and respiratory neurobiology. Disease burden, smoking, air pollution, and occupational exposure are studied with the tools of epidemiology and public health. Diagnosis leans on chest X-ray and CT, covered in radiology and medical imaging. Cardiology shares the pulmonary circulation: pulmonary hypertension sits between the two.

The closest institutional neighbor is critical care medicine, discussed below. In the United States the two are commonly trained and certified together, so many clinicians describe themselves as working in “pulmonary and critical care.”

A Short History

Respiratory medicine as a science developed from a series of instruments and ideas. Ibn al-Nafis, a 13th-century anatomist, proposed that blood passes through the lungs rather than through pores in the heart wall, as Galen had taught. In 1816 the French physician René Laënnec rolled a tube of paper to listen to a patient’s chest, an episode that led to the stethoscope, named from the Greek words for chest and watcher; see What Is a Stethoscope? for the instrument itself. In 1846 the surgeon John Hutchinson described a water spirometer and published measurements from more than 4,000 people, coining the term “vital capacity” and showing how it related to height and age. Spirometry remains a core test today.

Institutionally, much early organized lung medicine grew out of tuberculosis control. The American Thoracic Society, for example, was established in 1905 as the American Sanatorium Association and took its present name in 1960. Pulmonology took shape as a formal specialty in the mid-twentieth century as tuberculosis declined as the dominant concern and chronic airway disease, lung cancer, and intensive-care respiratory support took on greater weight.

Major Subspecialties and Research Areas

Pulmonary research and practice divide into several overlapping areas. The list below follows the topics that appear in clinical fellowships and in funders’ program descriptions, and is not an official taxonomy.

Obstructive airway disease: asthma and COPD, including their causes, exacerbations, and long-term treatment. Both are listed among the research areas of the U.S. National Heart, Lung, and Blood Institute (NHLBI).
Interstitial and fibrotic lung disease: conditions in which lung tissue becomes inflamed or scarred, including idiopathic pulmonary fibrosis and sarcoidosis.
Pulmonary vascular disease: pulmonary hypertension and pulmonary embolism. Risk-assessment rules used in this space are catalogued on this site, for example Wells criteria for DVT and PE and the PERC rule.
Sleep-disordered breathing: obstructive sleep apnea and related conditions. NHLBI’s lung division explicitly includes sleep and circadian biology in its remit, and practical aspects of treatment equipment are covered in CPAP and oxygen mask types.
Critical care and acute lung injury: acute respiratory distress syndrome (ARDS), pneumonia, sepsis, and mechanical ventilation.
Pediatric pulmonology and developmental lung biology: including bronchopulmonary dysplasia and cystic fibrosis.
Interventional pulmonology: a newer area using procedures such as bronchoscopy and pleuroscopy for diagnosis and treatment.
Infectious disease of the lung: tuberculosis and pneumonia, which connect pulmonology to infectious disease and public health.
Lung cancer, thoracic oncology, and lung transplantation: areas shared with oncology and surgery.
Environmental and occupational lung disease: the effects of dusts, fumes, and air pollution. The laboratory-safety side of this is addressed in respiratory protection programs for laboratories and What Is an N95 Respirator?

Pulmonology and Critical Care Medicine

Critical care medicine, the care of patients with life-threatening illness, is closely tied to pulmonology because respiratory failure and mechanical ventilation are central problems in intensive care. The American Board of Internal Medicine (ABIM) describes a combined pathway: candidates seeking dual certification in pulmonary disease and critical care medicine complete a minimum of three years of accredited combined training, and the pulmonary exam may be taken after two of the three years while the critical care exam follows completion of all three. That is a training-structure fact, not a claim that all critical care is pulmonary: critical care is a distinct discipline that spans organ systems.

For readers who work with intensive-care measurement tools, this site covers the APACHE II score, the SOFA and qSOFA scores, and the surveillance definition for ventilator-associated events.

Common Research Methods and Tools

Pulmonary research draws on methods at every scale, from molecule to population.

Lung function testing. Spirometry measures how much air a person can exhale and how fast. Fuller pulmonary function testing adds measures of lung volumes and of gas transfer. These tests are workhorses of both diagnosis and trial outcomes.
Gas exchange measurement. Arterial blood gas analysis and non-invasive pulse oximetry; see What Is a Pulse Oximeter?
Imaging. Chest radiography and CT, increasingly combined with quantitative image analysis.
Bronchoscopy and sampling. Direct airway inspection, with bronchoalveolar lavage and biopsy providing cells and fluid for laboratory analysis.
Sleep studies. Polysomnography to characterize breathing during sleep.
Cell and animal models. Airway epithelial cell culture, organoids, and rodent models of lung injury and disease. Human-relevant systems such as organ-on-a-chip devices are discussed in organ-on-a-chip as a replacement method.
Omics and genetics. Genomic, transcriptomic, and proteomic profiling to define disease subtypes; see What Is Proteomics?
Observational and clinical trial designs. Cohort studies, randomized trials, and increasingly adaptive designs such as basket and umbrella trials, compared in basket vs. umbrella vs. platform trials, as well as pragmatic trials run in routine care.

Trial Endpoints in Respiratory Research

Choosing an endpoint is among the most consequential design decisions in a respiratory trial, and reviewers and funders scrutinize it. Endpoints commonly seen in the field include:

Lung function measured by spirometry, most often the volume of air exhaled in the first second of a forced exhalation (FEV1). It is objective and sensitive but does not by itself capture how a patient feels or functions.
Exacerbation rates in chronic airway disease, a patient-relevant event count.
Patient-reported outcomes, such as symptom and quality-of-life questionnaires.
Mortality and ventilator-free days in critical care trials. Ventilator-free days is a composite that combines survival with time off mechanical ventilation over a fixed follow-up period.

One widely taught example of a critical-care trial is the ARDS Network low tidal volume study, published in the New England Journal of Medicine in 2000. It compared ventilation with tidal volumes of 6 mL per kg of predicted body weight against 12 mL per kg and was stopped after 861 patients were enrolled because mortality was lower in the lower-volume group (31.0% versus 39.8%), with more ventilator-free days (12 versus 10). It is cited here as an illustration of how a pulmonary-critical-care trial is framed around mortality and ventilator-free days, not as guidance for care. For general background on trial data and design vocabulary, see the dictionary entries on clinical trial data and the crossover study design.

How Pulmonary Research Is Funded

In the United States, the lead public funder of lung research is the NHLBI, part of the National Institutes of Health. Within NHLBI, the Division of Lung Diseases supports research on the causes, diagnosis, prevention, and treatment of lung diseases and sleep disorders. Its funded areas, as the institute describes them, include asthma, bronchopulmonary dysplasia, COPD, cystic fibrosis, respiratory neurobiology, sleep and circadian biology, sleep-disordered breathing, critical care and acute lung injury, developmental biology and pediatric pulmonary disease, immunologic and fibrotic lung disease, rare lung disorders, pulmonary vascular disease, and the pulmonary complications of AIDS and tuberculosis. Support flows through investigator-initiated grants, institute-initiated programs, and contracts.

Respiratory work can also fit programs at other NIH institutes depending on the angle: infectious and allergic disease, environmental health, cancer, and child health, for example. Beyond NIH, funding comes from other national agencies and research councils, from voluntary health organizations and disease foundations, and from industry sponsors of drug and device trials. Applicants should confirm each program’s current priorities directly with the funder, because they change from year to year. For how paylines work at NIH, see NIH paylines for FY2026.

The research-administration angle

Pulmonary studies raise grants-management issues that administrators see repeatedly. Human-subjects trials need IRB review, a data management plan, and clear definitions of endpoints and adverse events. Critical-care trials often enroll patients who cannot consent for themselves, which brings waiver and surrogate-consent rules into play. Animal-model work carries its own oversight, and bench work with aerosols or pathogens requires biosafety planning. Multi-site networks, as in the ARDS Network example above, add subaward and data-coordination complexity. For the hospital quality side of acute care, see the guide on failure to rescue.

Societies and Journals

Several professional societies organize the field. The American Thoracic Society (ATS) is an international society focused on respiratory and critical care medicine, and publishes the American Journal of Respiratory and Critical Care Medicine, the American Journal of Respiratory Cell and Molecular Biology, the Annals of the American Thoracic Society, and ATS Scholar. The American College of Chest Physicians (CHEST), founded in 1935, covers pulmonology, critical care, and sleep medicine. The European Respiratory Society (ERS) was founded in 1990 through the merger of two earlier European societies. The British Thoracic Society publishes Thorax, a journal established in 1946.

For researchers, society meetings and journals are where guidelines, consensus statements, and new methods circulate first. As always, check a journal’s current open-access, data-sharing, and preprint policies before submission.

Career and Training Pathways

In the United States, a physician pulmonologist typically completes medical school, an internal medicine residency, and then a fellowship in pulmonary disease, usually combined with critical care medicine. As described by ABIM, combined training is a minimum of three years, with a continuity outpatient clinic maintained throughout. Fellowship programs commonly build in protected time for a research or quality-improvement project; one program describes six of 36 months this way, though structures vary by institution. Pediatric pulmonology follows a pediatrics route. Outside the United States, training length and titles differ by country.

Research careers have additional routes: a PhD in physiology, cell biology, or a related field; physician-scientist pathways such as MD/PhD programs and research-focused fellowships; and roles in respiratory therapy, nursing science (see What Is Nursing Science?), epidemiology, and bioengineering. Research administrators supporting these groups work with clinical research offices, core facilities such as pulmonary function labs, and biosafety committees.

Frequently Asked Questions

What is pulmonology in simple terms?

Pulmonology is the medical and scientific field that deals with the lungs and breathing, including how they work and the diseases that affect them.

What is the difference between a pulmonologist and a respiratory therapist?

A pulmonologist is a physician who completes medical school and specialty fellowship training. A respiratory therapist is a clinician trained in delivering and managing respiratory treatments, including ventilators and oxygen therapy, through a separate education and credentialing route. Both can be part of research teams.

Is pulmonology the same as critical care?

No, but they overlap. Pulmonology covers respiratory disease in clinic and hospital. Critical care covers life-threatening illness of any organ system. In the United States many fellowships combine the two, which is why ABIM describes a combined pulmonary and critical care pathway.

Who funds pulmonary research?

In the U.S., NHLBI’s Division of Lung Diseases supports research on lung diseases and sleep disorders, with other NIH institutes, national agencies, voluntary health organizations, and industry also contributing.

What conditions fall under pulmonology?

Asthma, COPD, interstitial lung disease, pulmonary hypertension and embolism, sleep-disordered breathing, cystic fibrosis, pneumonia, tuberculosis, ARDS, and lung cancer (shared with oncology), among others.

How does one become a pulmonologist?

In the U.S., through medical school, internal medicine residency, and a pulmonary (often combined pulmonary and critical care) fellowship, followed by board certification. The combined pathway is at least three years.

What Is Pulmonology? Research Areas, Funding, and Career Paths