Pulmonology is a medical speciality that deals with diseases involving the respiratory tract.[1] The term is derived from the Latin word pulmō, pulmōnis ("lung") and the Greek suffix -λογία, -logia ("study of"). Pulmonology is synonymous with pneumology (from Greek πνεύμων ("lung") and -λογία), respirology and respiratory medicine.

Pulmonology is known as chest medicine and respiratory medicine in some countries and areas. Pulmonology is considered a branch of internal medicine, and is related to intensive care medicine. Pulmonology often involves managing patients who need life support and mechanical ventilation. Pulmonologists are specially trained in diseases and conditions of the chest, particularly pneumonia, asthma, tuberculosis, emphysema, and complicated chest infections. [2]

Respiratory system complete en
Schematic view of the human respiratory system with their parts and functions.
Significant diseasesAsthma, Lung Cancer, Tuberculosis, Occupational lung disease
Significant testsBronchoscopy, Sputum studies, Arterial blood gases
SpecialistRespiratory Physician, Pulmonologist

Variations in nomenclature

In the United Kingdom, the term "respiratory physiologist" is used[3]. In Ireland, South Africa, and Australia the term "respiratory physician" is used (rather than pulmonologist) to distinguish a physician that practices pulmonology. In Canada, respirology and respirologist are used [1]. Surgery of the respiratory tract is generally performed by specialists in cardiothoracic surgery (or thoracic surgery), though minor procedures may be performed by pulmonologists. As mentioned above, pulmonology is closely related to critical care medicine when dealing with patients who require mechanical ventilation. As a result, many pulmonologists are certified to practice critical care medicine in addition to pulmonary medicine. There are fellowship programs that allow physicians to become board certified in pulmonary and critical care medicine simultaneously. Interventional pulmonology is a relatively new field within pulmonary medicine that deals with the use of procedures such as bronchoscopy and pleuroscopy to treat several pulmonary diseases. Interventional pulmonology is increasingly recognized as a specific medical specialty.[4]


The pulmonologist begins the diagnostic process with a general review focusing on:

Physical diagnostics are as important as in the other fields of medicine.

As many heart diseases can give pulmonary signs, a thorough cardiac investigation is usually included.


Surgical procedures

Major surgical procedures on the heart and lungs are performed by a thoracic surgeon. Pulmonologists often perform specialized procedures to get samples from the inside of the chest or inside of the lung. They use radiographic techniques to view vasculature of the lungs and heart to assist with diagnosis.

Treatment and therapeutics

Medication is the most important treatment of most diseases of pulmonology, either by inhalation (bronchodilators and steroids) or in oral form (antibiotics, leukotriene antagonists). A common example being the usage of inhalers in the treatment of inflammatory lung conditions such as asthma or chronic obstructive pulmonary disease. Oxygen therapy is often necessary in severe respiratory disease (emphysema and pulmonary fibrosis). When this is insufficient, the patient might require mechanical ventilation.

Pulmonary rehabilitation has been defined as a multidimensional continuum of services directed to persons with pulmonary disease and their families, usually by an interdisciplinary team of specialists, with the goal of achieving and maintaining the individual's maximum level of independence and functioning in the community. Pulmonary rehabilitation is intended to educate the patient, the family, and improve the overall quality of life and prognosis for the patient. Interventions can include exercise, education, emotional support, oxygen, noninvasive mechanical ventilation, optimization of airway secretion clearance, promoting compliance with medical care to reduce numbers of exacerbations and hospitalizations, and returning to work and/or a more active and emotionally satisfying life. These goals are appropriate for any patients with diminished respiratory reserve whether due to obstructive or intrinsic pulmonary diseases (oxygenation impairment) or neuromuscular weakness (ventilatory impairment). A pulmonary rehabilitation team may include a rehabilitation physician, a pulmonary medicine specialist, and allied health professionals including a rehabilitation nurse, a respiratory therapist, a physical therapist, an occupational therapist, a psychologist, and a social worker among others. Additionally breathing games are used to motivate children to perform pulmonary rehabilitation.

Education and training

Bronchoscopy nci-vol-1950-300
Physician performing a bronchoscopy.
  • Pulmonologist
  • Pneumonologist
  • Respirologist
Occupation type
Activity sectors
Education required
Fields of
Hospitals, clinics

In the United States, pulmonologists are physicians who, after receiving a medical degree (MD or DO), complete residency training in internal medicine, followed by at least two additional years of subspeciality fellowship training in pulmonology. After satisfactorily completing a fellowship in pulmonary medicine, the physician is permitted to take the board certification examination in pulmonary medicine. After passing this exam, the physician is then board certified as a pulmonologist. Most pulmonologists complete three years of combined subspecialty fellowship training in pulmonary medicine and critical care medicine.

Pediatric pulmonologist

In the United States, pediatric pulmonologists are physicians who, after receiving a medical degree (MD or DO), complete residency training in pediatrics, followed by at least three additional years of subspeciality fellowship training in pulmonology.

Scientific research

Pulmonologists are involved in both clinical and basic research of the respiratory system, ranging from the anatomy of the respiratory epithelium to the most effective treatment of pulmonary hypertension. Scientific research also takes place to look for causes and possible treatment in diseases such as pulmonary tuberculosis and lung cancer.

Journals of pulmonology

History of pulmonology

One of the first major discoveries relevant to the field of pulmonology was the discovery of pulmonary circulation. Originally, it was thought that blood reaching the right side of the heart passed through small 'pores' in the septum into the left side to be oxygenated, as theorized by Galen; however, the discovery of pulmonary circulation disproves this theory, which had previously been accepted since the 2nd century. Thirteenth century anatomist and physiologist Ibn Al-Nafis accurately theorized that there was no 'direct' passage between the two sides (ventricles) of the heart. He believed that the blood must have passed through the pulmonary artery, through the lungs, and back into the heart to be pumped around the body. This is believed by many to be the first scientific description of pulmonary circulation.[5]

Although pulmonary medicine only began to evolve as a medical specialty in the 1950s, William Welch and William Osler founded the 'parent' organization of the American Thoracic Society, the National Association for the Study and Prevention of Tuberculosis. The care, treatment, and study of tuberculosis of the lung is recognised as a discipline in its own right, phthisiology. When the specialty did begin to evolve, several discoveries were being made linking the respiratory system and the measurement of arterial blood gases, attracting more and more physicians and researchers to the developing field.[6]


  1. ^ ACP: Pulmonology: Internal Medicine Subspecialty. Acponline.org. Retrieved on 2011-09-30.
  2. ^ Sengupta, Nandini; Sahidullah, Md; Saha, Goutam (August 2016). "Lung sound classification using cepstral-based statistical features". Computers in Biology and Medicine. 75 (1): 118–129. doi:10.1016/j.compbiomed.2016.05.013.
  3. ^ "Respiratory physiology and sleep sciences".
  4. ^ Luis M. Seijo & Daniel H. Sterman (2001). "Interventional Pulmonology". N. Engl. J. Med. 344 (10): 740–49. doi:10.1056/NEJM200103083441007. PMID 11236779.
  5. ^ Sharif Kaf A-Ghazal (2002). "The discovery of the pulmonary circulation – who should get the credit: ibn Al-Nafis or William Harvey" (PDF). JISHIM. 2: 46.
  6. ^ History of the Division. Hopkinsmedicine.org. Retrieved on 2011-09-30.
American College of Chest Physicians

The American College of Chest Physicians (CHEST) is a medical association in the United States consisting of physicians and non-physician specialists in the field of chest medicine, which includes pulmonology, critical care medicine, and sleep medicine. The group was founded in 1935.

American Lung Association

The American Lung Association is a voluntary health organization whose mission is to save lives by improving lung health and preventing lung disease through education, advocacy and research.

American Thoracic Society

The American Thoracic Society (ATS) is a nonprofit organization focused on improving care for pulmonary diseases, critical illnesses and sleep-related breathing disorders. It was established in 1905 as the American Sanatorium Association, and changed its name in 1938 to the American Trudeau Society. In 1960, it changed its name again to the American Thoracic Society. Originally the medical section of the American Lung Association, the Society became independently incorporated in 2000 as a 501 (c) (3) organization.


Baritosis is a benign type of pneumoconiosis, which is caused by long-term exposure to barium dust.

Barium has a high radio-opacity and the disease may develop after few months of exposure. Extremely dense, discrete small opacities of 2–4 mm diameter, sometimes of a star-like configuration, are seen on the radiograph. Their distribution is uniform. When they are very numerous, superimposition may give the impression of confluency, but this does not seem to occur in reality. The hilar lymph nodes can be very opaque but not enlarged. After cessation of exposure, there is a gradual clearing of the opacities.

Blood gas tension

Blood gas tension refers to the partial pressure of gases in blood. There are several significant purposes for measuring gas tension; the most common gas tensions measured are oxygen tension (PxO2), the carbon dioxide tension (PxCO2) and carbon monoxide tension (PxCO). The subscript x in each symbol represents the source of the gas being measured; "a" meaning arterial, "A" being alveolar, "v" being venous, "c" being capillary. Blood gas tests (such as arterial blood gas tests) measure these partial pressures.

Blood gas test

A blood gas test or blood gas analysis tests blood to measure blood gas tension values, it also measures blood pH, and the level and base excess of bicarbonate. The source of the blood is reflected in the name of each test; arterial blood gases come from arteries, venous blood gases come from veins and capillary blood gases come from capillaries. The blood gas tension levels of partial pressures can be used as indicators of ventilation, respiration and oxygenation. Analysis of paired arterial and venous specimens can give insights into the aetiology of acidosis in the newborn.


is age a parameter

CURB-65, also known as the CURB criteria, is a clinical prediction rule that has been validated for predicting mortality in community-acquired pneumonia and infection of any site. The CURB-65 is based on the earlier CURB score and is recommended by the British Thoracic Society for the assessment of severity of pneumonia. It was developed in 2002 at the University of Nottingham by Dr. W.S. Lim et al. In 2018 a new toolkit was presented on the basis of CURB-65. The score is an acronym for each of the risk factors measured. Each risk factor scores one point, for a maximum score of 5:

Confusion of new onset (defined as an AMTS of 8 or less)

Blood Urea nitrogen greater than 7 mmol/l (19 mg/dL)

Respiratory rate of 30 breaths per minute or greater

Blood pressure less than 90 mmHg systolic or diastolic blood pressure 60 mmHg or less

Age 65 or older

Chest (journal)

Chest is a peer-reviewed medical journal covering chest diseases and related issues, including pulmonology, cardiology, thoracic surgery, transplantation, breathing, airway diseases, and emergency medicine. The journal was established in 1935. It is the official journal of the American College of Chest Physicians which publishes the journal. The editor-in-chief is Richard S. Irwin (University of Massachusetts Medical School).

Curschmann's spirals

Curschmann's spirals are a microscopic finding in the sputum of asthmatics. They are spiral-shaped mucus plugs from subepithelial mucous gland ducts of bronchi. They may occur in several different lung diseases.and may refer to parts of the desquamated epithelium seen in lavages from asthmatic patients. These microscopic casts are named after German physician Heinrich Curschmann (1846-1910). They are often seen in association with creola bodies and Charcot-Leyden crystals. They are elongated microscopic mucous casts from small bronchi and are often found in sputum samples from patients with bronchial asthma. They can be stretched out to a length of around 2 cm and can sometimes be longer. They have a central core that may be ensheathed in cell debris and mucus.

Fraction of inspired oxygen

Fraction of inspired oxygen (FiO2) is the fraction of oxygen in the volume being measured. Medical patients experiencing difficulty breathing are provided with oxygen-enriched air, which means a higher-than-atmospheric FiO2. Natural air includes 21% oxygen, which is equivalent to FiO2 of 0.21. Oxygen-enriched air has a higher FiO2 than 0.21; up to 1.00 which means 100% oxygen. FiO2 is typically maintained below 0.5 even with mechanical ventilation, to avoid oxygen toxicity.Often used in medicine, the FiO2 is used to represent the percentage of oxygen participating in gas-exchange. If the barometric pressure changes, the FiO2 may remain constant while the partial pressure of oxygen changes with the change in barometric pressure.


Lobectomy means surgical excision of a lobe. This may refer to a lobe of the lung, a lobe of the thyroid (hemithyroidectomy), or a lobe of the brain (as in anterior temporal lobectomy).

Lung allocation score

The lung allocation score (LAS) is a numerical value used by the United Network for Organ Sharing (UNOS) to assign relative priority for distributing donated lungs for transplantation within the United States. The lung allocation score takes into account various measures of a patient's health in order to direct donated organs towards the patients who would best benefit from a lung transplant.

The LAS system replaces the older method within the United States of allocating donated lungs strictly on a first-come, first-served basis, according to blood type compatibility and distance from the donor hospital. The older method is still used for patients under the age of 12.

The LAS system is still being evaluated and revised. The reason for this continuing analysis is the need to balance on one hand the desire to help those patients in direct need, versus the statistical likelihood of the patient to survive the procedure, as well as the post-operative risks of infection and transplant rejection.


Mucokinetics are a class of drugs which aid in the clearance of mucus from the airways, lungs, bronchi, and trachea. Such drugs can be further categorized by their mechanism of action:

mucolytic agents



wetting agents (hypoviscosity agents)

abhesivesIn general, clearance ability is hampered by bonding to surfaces (stickiness) and by the viscosity of mucous secretions in the lungs. In turn, the viscosity is dependent upon the concentration of mucoprotein in the secretions.

Expectorants and mucolytic agents are different types of medication, yet both are intended to promote drainage of mucus from the lungs.

An expectorant (from the Latin expectorare, to expel or banish) works by signaling the body to increase the amount or hydration of secretions, resulting in more yet clearer secretions and as a byproduct lubricating the irritated respiratory tract. One expectorant, guaifenesin, is commonly available in many cough syrups. Often the term "expectorant" is incorrectly extended to any cough medicine, since it is a universal component.A mucolytic agent is an agent which dissolves thick mucus and is usually used to help relieve respiratory difficulties. It does so by dissolving various chemical bonds within secretions, which in turn can lower the viscosity by altering the mucin-containing components.

Alternatively, attacking the affinity between secretions and the biological surfaces is another avenue, which is used by abhesives and surfactants.

Any of these effects could improve airway clearance during coughing.

An expectorant increases bronchial secretions and mucolytics help loosen thick bronchial secretions. Expectorants reduce the thickness or viscosity of bronchial secretions thus increasing mucus flow that can be removed more easily through coughing. Mucolytics break down the chemical structure of mucus molecules. The mucus becomes thinner and can be removed more easily through coughing.


Normocapnia or normocarbia is a state of normal arterial carbon dioxide pressure, usually about 40 mmHg.

Oxygen saturation (medicine)

Oxygen saturation is the fraction of oxygen-saturated hemoglobin relative to total hemoglobin (unsaturated + saturated) in the blood. The human body requires and regulates a very precise and specific balance of oxygen in the blood. Normal blood oxygen levels in humans are considered 95–100 percent. If the level is below 90 percent, it is considered low resulting in hypoxemia. Blood oxygen levels below 80 percent may compromise organ function, such as the brain and heart, and should be promptly addressed. Continued low oxygen levels may lead to respiratory or cardiac arrest. Oxygen therapy may be used to assist in raising blood oxygen levels. Oxygenation occurs when oxygen molecules (O2) enter the tissues of the body. For example, blood is oxygenated in the lungs, where oxygen molecules travel from the air and into the blood. Oxygenation is commonly used to refer to medical oxygen saturation.

Peak inspiratory pressure

Peak inspiratory pressure (PIP) is the highest level of pressure applied to the lungs during inhalation. In mechanical ventilation the number reflects a positive pressure in centimeters of water pressure (cmH2O). In normal breathing, it may sometimes be referred to as the maximal inspiratory pressure (MIPO), which is a negative value.Peak inspiratory pressure increases with any airway resistance. Things that may increase PIP could be increased secretions, bronchospasm, biting down on ventilation tubing, and decreased lung compliance. PIP should never be chronically higher than 40(cmH2O) unless the patient has acute respiratory distress syndrome.

Respiratory sounds

Respiratory sounds, breath sounds, or lung sounds refer to the specific sounds generated by the movement of air through the respiratory system. These may be easily audible or identified through auscultation of the respiratory system through the lung fields with a stethoscope as well as from the spectral chacteristics of lung sounds. These include normal breath sounds and adventitious or "added" sounds such as rales, wheezes, pleural friction rubs, stertor and stridor.

Description and classification of the sounds usually involve auscultation of the inspiratory and expiratory phases of the breath cycle, noting both the pitch (typically described as low, medium or high) and intensity (soft, medium, loud or very loud) of the sounds heard.

Smoke inhalation

Smoke inhalation is the primary cause of death for victims of fires. The inhalation or exposure to hot gaseous products of combustion can cause serious respiratory complications.Some 50–80% of fire deaths are the result of smoke inhalation injuries, including burns to the respiratory system. The hot smoke injures or kills by a combination of thermal damage, poisoning and pulmonary irritation and swelling, caused by carbon monoxide, cyanide and other combustion products.

Ventilator-associated lung injury

Ventilator-associated lung injury (VALI) is an acute lung injury that develops during mechanical ventilation and is termed ventilator-induced lung injury (VILI) if it can be proven that the mechanical ventilation caused the acute lung injury. In contrast, ventilator-associated lung injury (VALI) exists if the cause cannot be proven. VALI is the appropriate term in most situations because it is virtually impossible to prove what actually caused the lung injury in the hospital.

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