Respiratory disease

Micrograph of an emphysematous lung; emphysema is a common respiratory disease, strongly associated with smoking. H&E stain.
Specialty| Pulmonology

Respiratory diseases, or lung diseases,[1] are pathological conditions affecting the organs and tissues that make gas exchange difficult in air-breathing animals. They include conditions of the respiratory tract including the trachea, bronchi, bronchioles, alveoli, pleurae, pleural cavity, the nerves and muscles of respiration. Respiratory diseases range from mild and self-limiting, such as the common cold, influenza, and pharyngitis to life-threatening diseases such as bacterial pneumonia, pulmonary embolism, tuberculosis, acute asthma, lung cancer,[2] and severe acute respiratory syndromes, such as COVID-19.[3] Respiratory diseases can be classified in many different ways, including by the organ or tissue involved, by the type and pattern of associated signs and symptoms, or by the cause of the disease.

The study of respiratory disease is known as pulmonology. A physician who specializes in respiratory disease is known as a pulmonologist, a chest medicine specialist, a respiratory medicine specialist, a respirologist or a thoracic medicine specialist.

## Contents

* 1 Obstructive lung disease
* 2 Restrictive lung diseases
* 3 Chronic respiratory disease
* 4 Respiratory tract infections
* 4.1 Upper respiratory tract infection
* 4.2 Lower respiratory tract infection
* 5 Tumors
* 5.1 Malignant tumors
* 5.2 Benign tumors
* 6 Pleural cavity diseases
* 7 Pulmonary vascular disease
* 8 Neonatal diseases
* 9 Diagnosis
* 10 Epidemiology
* 11 References
* 12 External links

## Obstructive lung disease[edit | edit source]

Asthma, chronic bronchitis, bronchiectasis and chronic obstructive pulmonary disease (COPD) are all obstructive lung diseases characterised by airway obstruction. This limits the amount of air that is able to enter alveoli because of constriction of the bronchial tree, due to inflammation. Obstructive lung diseases are often identified because of symptoms and diagnosed with pulmonary function tests such as spirometry. Many obstructive lung diseases are managed by avoiding triggers (such as dust mites or smoking), with symptom control such as bronchodilators, and with suppression of inflammation (such as through corticosteroids) in severe cases. One common cause of COPD including emphysema, and chronic bronchitis, is tobacco smoking, and common causes of bronchiectasis include severe infections and cystic fibrosis. The definitive cause of asthma is not yet known.[4]

## Restrictive lung diseases[edit | edit source]

Age-standardised disability-adjusted life year (DALY) rates from respiratory diseases by country (per 100,000 inhabitants).

Restrictive lung diseases are a category of respiratory disease characterized by a loss of lung compliance,[5] causing incomplete lung expansion and increased lung stiffness, such as in infants with respiratory distress syndrome. Restrictive lung diseases can be divided into two categories: those caused by intrinsic factors and those caused by extrinsic factors. Restrictive lung diseases yielding from intrinsic factors occur within the lungs themselves, such as tissue death due to inflammation or toxins. Conversely, restrictive lung diseases caused by extrinsic factors result from conditions originating from outside the lungs such as neuromuscular dysfunction and irregular chest wall movements.[6]

## Chronic respiratory disease[edit | edit source]

Chronic respiratory diseases (CRDs) are long-term diseases of the airways and other structures of the lung. They are characterized by a high inflammatory cell recruitment (neutrophil) and/or destructive cycle of infection, (e.g. mediated by Pseudomonas aeruginosa). Some of the most common are asthma, chronic obstructive pulmonary disease, and acute respiratory distress syndrome. CRDs are not curable; however, various forms of treatment that help dilate major air passages and improve shortness of breath can help control symptoms and increase the quality of life.[7]

Telerehabilitation for chronic respiratory disease

The latest evidence suggests that primary pulmonary rehabilitation and maintenance rehabilitation delivered through telerehabilitation for people with chronic respiratory disease reaches outcomes similar to centre-based rehabilitation.[8] While there are no safety issues identified, the findings are based on evidence limited by a small number of studies.[8]

## Respiratory tract infections[edit | edit source]

Infections can affect any part of the respiratory system. They are traditionally divided into upper respiratory tract infections and lower respiratory tract infections.

### Upper respiratory tract infection[edit | edit source]

The most common upper respiratory tract infection is the common cold. However, infections of specific organs of the upper respiratory tract such as sinusitis, tonsillitis, otitis media, pharyngitis and laryngitis are also considered upper respiratory tract infections.

### Lower respiratory tract infection[edit | edit source]

Respiratory syncytial virus in cross-section on the surface of a human respiratory endothelial cell[9][10]

The most common lower respiratory tract infection is pneumonia, an infection of the lungs which is usually caused by bacteria, particularly Streptococcus pneumoniae in Western countries. Worldwide, tuberculosis is an important cause of pneumonia. Other pathogens such as viruses and fungi can cause pneumonia for example severe acute respiratory syndrome, COVID-19 and pneumocystis pneumonia. Pneumonia may develop complications such as a lung abscess, a round cavity in the lung caused by the infection, or may spread to the pleural cavity.

Poor oral care may be a contributing factor to lower respiratory disease. as bacteria from gum disease may travel through airways and into the lungs.[11][12]

## Tumors[edit | edit source]

### Malignant tumors[edit | edit source]

Malignant tumors of the respiratory system, particularly primary carcinomas of the lung, are a major health problem responsible for 15% of all cancer diagnoses and 30% of all cancer deaths. The majority of respiratory system cancers are attributable to smoking tobacco.

The major histological types of respiratory system cancer are:

* Small cell lung cancer
* Non-small cell lung cancer
* Adenocarcinoma of the lung
* Squamous cell carcinoma of the lung
* Large cell lung carcinoma
* Other lung cancers (carcinoid, Kaposi’s sarcoma, melanoma)
* Lymphoma
* Head and neck cancer
* Pleural mesothelioma, almost always caused by exposure to asbestos dust.

In addition, since many cancers spread via the bloodstream and the entire cardiac output passes through the lungs, it is common for cancer metastases to occur within the lung. Breast cancer may invade directly through local spread, and through lymph node metastases. After metastasis to the liver, colon cancer frequently metastasizes to the lung. Prostate cancer, germ cell cancer and renal cell carcinoma may also metastasize to the lung.

Treatment of respiratory system cancer depends on the type of cancer. Surgical removal of part of a lung (lobectomy, segmentectomy, or wedge resection) or of an entire lung pneumonectomy), along with chemotherapy and radiotherapy, are all used. The chance of surviving lung cancer depends on the cancer stage at the time the cancer is diagnosed, and to some extent on the histology, and is only about 14–17% overall. In the case of metastases to the lung, treatment can occasionally be curative but only in certain, rare circumstances.

### Benign tumors[edit | edit source]

Benign tumors are relatively rare causes of respiratory disease. Examples of benign tumors are:

* Pulmonary hamartoma
* Congenital malformations such as pulmonary sequestration and congenital cystic adenomatoid malformation (CCAM).

## Pleural cavity diseases[edit | edit source]

Pleural cavity diseases include pleural mesothelioma which are mentioned above.

A collection of fluid in the pleural cavity is known as a pleural effusion.[13] This may be due to fluid shifting from the bloodstream into the pleural cavity due to conditions such as congestive heart failure and cirrhosis.[13] It may also be due to inflammation of the pleura itself as can occur with infection, pulmonary embolus, tuberculosis, mesothelioma and other conditions.[13]

A pneumothorax is a hole in the pleura covering the lung allowing air in the lung to escape into the pleural cavity. The affected lung "collapses" like a deflated balloon. A tension pneumothorax is a particularly severe form of this condition where the air in the pleural cavity cannot escape, so the pneumothorax keeps getting bigger until it compresses the heart and blood vessels, leading to a life-threatening situation.

## Pulmonary vascular disease[edit | edit source]

Pulmonary vascular diseases are conditions that affect the pulmonary circulation. Examples are:[citation needed]

* Pulmonary embolism, a blood clot that forms in a vein, breaks free, travels through the heart and lodges in the lungs (thromboembolism). Large pulmonary emboli are fatal, causing sudden death. A number of other substances can also embolise (travel through the blood stream) to the lungs but they are much more rare: fat embolism (particularly after bony injury), amniotic fluid embolism (with complications of labour and delivery), air embolism (iatrogenic – caused by invasive medical procedures).
* Pulmonary arterial hypertension, elevated pressure in the pulmonary arteries. Most commonly it is idiopathic (i.e. of unknown cause) but it can be due to the effects of another disease, particularly COPD. This can lead to strain on the right side of the heart, a condition known as cor pulmonale.
* Pulmonary edema, leakage of fluid from capillaries of the lung into the alveoli (or air spaces). It is usually due to congestive heart failure.
* Pulmonary hemorrhage, inflammation and damage to capillaries in the lung resulting in blood leaking into the alveoli. This may cause blood to be coughed up. Pulmonary hemorrhage can be due to auto-immune disorders such as granulomatosis with polyangiitis and Goodpasture's syndrome.

## Neonatal diseases[edit | edit source]

Pulmonary diseases may also impact newborns, such as pulmonary hyperplasia, pulmonary interstitial emphysema (usually preterm births), and infant respiratory distress syndrome.

## Diagnosis[edit | edit source]

Respiratory diseases may be investigated by performing one or more of the following tests

* Biopsy of the lung or pleura
* Blood test
* Bronchoscopy
* Chest X-ray
* CT scan, including high-resolution computed tomography
* Culture of microorganisms from secretions such as sputum
* Ultrasound scanning can be useful to detect fluid such as pleural effusion
* Pulmonary function test
* Ventilation–perfusion scan

## Epidemiology[edit | edit source]

Respiratory disease is a common and significant cause of illness and death around the world. In the US, approximately one billion common colds occur each year.[14] A study found that in 2010, there were approximately 6.8 million emergency department visits for respiratory disorders in the U.S. for patients under the age of 18.[15] In 2012, respiratory conditions were the most frequent reasons for hospital stays among children.[16]

In the UK, approximately 1 in 7 individuals are affected by some form of chronic lung disease, most commonly chronic obstructive pulmonary disease, which includes asthma, chronic bronchitis and emphysema.[17] Respiratory diseases (including lung cancer) are responsible for over 10% of hospitalizations and over 16% of deaths in Canada.[18]

In 2011, respiratory disease with ventilator support accounted for 93.3% of ICU utilization in the United States.[19]

## References[edit | edit source]

1. ↑ "Lung diseases". MeSH.nlm.nih.gov. Archived from the original on 12 June 2020. Retrieved 14 August 2019.
2. ↑ Sengupta N, Sahidullah M, Saha G (August 2016). "Lung sound classification using cepstral-based statistical features". Computers in Biology and Medicine. 75 (1): 118–29. doi:10.1016/j.compbiomed.2016.05.013. PMID 27286184.
3. ↑ "COVID-19 and vascular disease". EBioMedicine. 58: 102966. August 2020. doi:10.1016/j.ebiom.2020.102966. PMC 7438984. PMID 32829782.
4. ↑ Reid PT, Innes JA (2014). "Respiratory Diseases". In Walker BR, Colledge NR, Ralston SH, Penman I (eds.). Davidson's Principles and Practice of Medicine (22nd ed.). Elsevier Health Sciences. pp. 661–730. ISBN 978-0-7020-5035-0.
5. ↑ Sharma S (5 June 2006). Grier LR, Ouellette DR, Mosenifar Z (eds.). "Restrictive Lung Disease". Medscape. Archived from the original on 19 December 2008. Retrieved 2008-04-19.
6. ↑ Martinez-Pitre PJ, Sabbula BR, Cascella M (2020). "Restrictive Lung Disease". StatPearls. Treasure Island (FL): StatPearls Publishing. PMID 32809715. Archived from the original on 2022-01-28. Retrieved 2020-12-04.
7. ↑ "Chronic respiratory diseases (CRDs)". World Health Organization. Archived from the original on 2018-10-30. Retrieved 2022-01-26.
8. ↑ 8.0 8.1 Cox NS, Dal Corso S, Hansen H, McDonald CF, Hill CJ, Zanaboni P, et al. (Cochrane Airways Group) (January 2021). "Telerehabilitation for chronic respiratory disease". The Cochrane Database of Systematic Reviews. 1 (1): CD013040. doi:10.1002/14651858.CD013040.pub2. PMC 8095032. PMID 33511633.`{{cite journal}}`: CS1 maint: PMC embargo expired (link)
9. ↑ Smith, Dustin K.; Seales, Sajeewane; Budzik, Carol (15 January 2017). "Respiratory Syncytial Virus Bronchiolitis in Children". American Family Physician. 95 (2): 94–99. Retrieved 22 February 2024.
10. ↑ Bianchini, Sonia; Silvestri, Ettore; Argentiero, Alberto; Fainardi, Valentina; Pisi, Giovanna; Esposito, Susanna (21 December 2020). "Role of Respiratory Syncytial Virus in Pediatric Pneumonia". Microorganisms. 8 (12): 2048. doi:10.3390/microorganisms8122048. ISSN 2076-2607.
11. ↑ "Respiratory Disease & Oral Health". United Concordia Companies, Inc. Archived from the original on 2016-03-04. Retrieved 2022-01-26.
12. ↑ Gomes-Filho IS, Passos JS, Seixas da Cruz S (December 2010). "Respiratory disease and the role of oral bacteria". Journal of Oral Microbiology. 2: 5811. doi:10.3402/jom.v2i0.5811. PMC 3084574. PMID 21523216.
13. ↑ 13.0 13.1 13.2 Karkhanis VS, Joshi JM (2012-06-22). "Pleural effusion: diagnosis, treatment, and management". Open Access Emergency Medicine. 4: 31–52. doi:10.2147/OAEM.S29942. PMC 4753987. PMID 27147861.
14. ↑ "National Institutes of Health – common cold". Archived from the original on 2008-10-01. Retrieved 2008-05-07.
15. ↑ Wier LM, Yu H, Owens PL, Washington R (May 2013). "Overview of Children in the Emergency Department, 2010". HCUP Statistical Brief #157. Agency for Healthcare Research and Quality. PMID 24006551. Archived from the original on 2013-12-03. Retrieved 2022-01-26.
16. ↑ Witt WP, Wiess AJ, Elixhauser A (December 2014). "Overview of Hospital Stays for Children in the United States, 2012". HCUP Statistical Brief #186. Rockville, MD: Agency for Healthcare Research and Quality. Archived from the original on 2018-09-24. Retrieved 2022-01-26.
17. ↑ "What is COPD?". British Lung Foundation. 7 September 2015. Archived from the original on 20 January 2022. Retrieved 26 January 2022.
18. ↑ "Public Health Agency of Canada – Centre for Chronic Disease Prevention and Control Chronic Respiratory Diseases". Archived from the original on 2008-04-11. Retrieved 2008-05-06.
19. ↑ Barrett ML, Smith MW, Elizhauser A, Honigman LS, Pines JM (December 2014). "Utilization of Intensive Care Services, 2011". HCUP Statistical Brief #185. Rockville, MD: Agency for Healthcare Research and Quality. Archived from the original on 2015-04-02. Retrieved 2022-01-26.

## External links[edit | edit source]

Classification|

* ICD-10: J00-J99
* ICD-9-CM: 460-519
* MeSH: D012140

|

* v
* t
* e

Diseases of the respiratory system

Upper RT
(including URTIs,
common cold)|

| Head|

sinuses

Sinusitis

nose

Rhinitis

Vasomotor rhinitis
Atrophic rhinitis
Hay fever
Nasal polyp
Rhinorrhea
nasal septum

Nasal septum deviation
Nasal septum perforation
Nasal septal hematoma

tonsil

Tonsillitis
Adenoid hypertrophy
Peritonsillar abscess

|

Neck|

pharynx

Pharyngitis

Strep throat
Laryngopharyngeal reflux (LPR)
Retropharyngeal abscess

larynx

Croup
Laryngomalacia
Laryngeal cyst
Laryngitis
Laryngopharyngeal reflux (LPR)
Laryngospasm

vocal cords

Laryngopharyngeal reflux (LPR)
Vocal fold nodule
Vocal fold paresis
Vocal cord dysfunction

epiglottis

Epiglottitis

trachea

Tracheitis
Laryngotracheal stenosis

Lower RT/lung disease
(including LRTIs)|

| Bronchial/
obstructive|

acute

Acute bronchitis

chronic

COPD

Chronic bronchitis
Acute exacerbation of COPD)
Asthma (Status asthmaticus
Aspirin-induced
Exercise-induced
Bronchiectasis
Cystic fibrosis

unspecified

Bronchitis
Bronchiolitis

Bronchiolitis obliterans
Diffuse panbronchiolitis

|

Interstitial/
restrictive
(fibrosis)|

| External agents/
occupational
lung disease|

Pneumoconiosis

Aluminosis
Asbestosis
Baritosis
Bauxite fibrosis
Berylliosis
Caplan's syndrome
Chalicosis
Coalworker's pneumoconiosis
Siderosis
Silicosis
Talcosis
Byssinosis

Hypersensitivity pneumonitis

Bagassosis
Bird fancier's lung
Farmer's lung
Lycoperdonosis

|

Other|

* ARDS
* Combined pulmonary fibrosis and emphysema
* Pulmonary edema
* Löffler's syndrome/Eosinophilic pneumonia
* Respiratory hypersensitivity
* Allergic bronchopulmonary aspergillosis
* Hamman-Rich syndrome
* Idiopathic pulmonary fibrosis
* Sarcoidosis
* Vaping-associated pulmonary injury

Obstructive / Restrictive|

| Pneumonia/
pneumonitis|

| By pathogen|

* Viral
* Bacterial
* Pneumococcal
* Klebsiella
* Atypical bacterial
* Mycoplasma
* Legionnaires' disease
* Chlamydiae
* Fungal
* Pneumocystis
* Parasitic
* noninfectious
* Chemical/Mendelson's syndrome
* Aspiration/Lipid

|

By vector/route|

* Community-acquired
* Healthcare-associated
* Hospital-acquired

By distribution|

* Broncho-
* Lobar

IIP|

* UIP
* DIP
* BOOP-COP
* NSIP
* RB

Other|

* Atelectasis
* circulatory
* Pulmonary hypertension
* Pulmonary embolism
* Lung abscess

Pleural cavity/
mediastinum|

| Pleural disease|

* Pleuritis/pleurisy

* Pneumothorax/Hemopneumothorax

Pleural effusion

Hemothorax
Hydrothorax
Chylothorax
Empyema/pyothorax
Malignant

Fibrothorax

|

Mediastinal disease|

* Mediastinitis
* Mediastinal emphysema

Other/general|

* Respiratory failure
* Influenza
* Common cold
* SARS
* COVID-19
* Idiopathic pulmonary haemosiderosis
* Pulmonary alveolar proteinosis

* v
* t
* e

Conditions originating in the perinatal period / fetal disease

Maternal factors
complicating pregnancy,
labour or delivery|

| placenta|

* Placenta praevia
* Placental insufficiency
* Twin-to-twin transfusion syndrome

|

chorion/amnion|

* Chorioamnionitis

umbilical cord|

* Umbilical cord prolapse
* Nuchal cord
* Single umbilical artery

presentation|

* Breech birth
* Asynclitism
* Shoulder presentation

Growth|

* Small for gestational age / Large for gestational age
* Preterm birth / Postterm pregnancy
* Intrauterine growth restriction

Birth trauma|

* scalp
* Cephalohematoma
* Chignon
* Caput succedaneum
* Subgaleal hemorrhage
* Brachial plexus injury
* Erb's palsy
* Klumpke paralysis

Affected systems|

| Respiratory|

* Intrauterine hypoxia
* Infant respiratory distress syndrome
* Transient tachypnea of the newborn
* Meconium aspiration syndrome
* Pleural disease
* Pneumothorax
* Pneumomediastinum
* Wilson–Mikity syndrome
* Bronchopulmonary dysplasia

|

Cardiovascular|

* Pneumopericardium
* Persistent fetal circulation

Bleeding and
hematologic disease|

* Vitamin K deficiency bleeding

* HDN
* ABO
* Anti-Kell
* Rh c
* Rh D
* Rh E
* Hydrops fetalis
* Hyperbilirubinemia
* Kernicterus
* Neonatal jaundice

* Velamentous cord insertion
* Intraventricular hemorrhage
* Germinal matrix hemorrhage
* Anemia of prematurity

Gastrointestinal|

* Ileus
* Necrotizing enterocolitis
* Meconium peritonitis

Integument and
thermoregulation|

* Erythema toxicum
* Sclerema neonatorum

Nervous system|

* Perinatal asphyxia
* Periventricular leukomalacia

Musculoskeletal|

* Gray baby syndrome
* muscle tone
* Congenital hypertonia
* Congenital hypotonia

Infections|

* Vertically transmitted infection
* Neonatal infection
* rubella
* herpes simplex
* mycoplasma hominis
* ureaplasma urealyticum
* Omphalitis
* Neonatal sepsis
* Group B streptococcal infection
* Neonatal conjunctivitis

Other|

* Miscarriage
* Perinatal mortality
* Stillbirth
* Infant mortality
* Neonatal withdrawal

* v
* t
* e

Respiratory physiology

Respiration|

* breath
* inhalation
* exhalation
* obligate nasal breathing
* respiratory rate
* respirometer
* pulmonary surfactant
* compliance
* elastic recoil
* hysteresivity
* airway resistance
* bronchial
* hyperresponsiveness
* constriction
* dilatation
* mechanical ventilation

Control|

* pons
* pneumotaxic center
* apneustic center
* medulla
* dorsal respiratory group
* ventral respiratory group
* chemoreceptors
* central
* peripheral
* pulmonary stretch receptors
* Hering–Breuer reflex

Lung volumes|

* VC
* FRC
* Vt
* dead space
* CC
* PEF

calculations

respiratory minute volume
FEV1/FVC ratio

Lung function tests

spirometry
body plethysmography
peak flow meter
nitrogen washout

Circulation|

* pulmonary circulation
* hypoxic pulmonary vasoconstriction
* pulmonary shunt

Interactions|

* ventilation (V)
* Perfusion (Q)
* Ventilation/perfusion ratio
* V/Q scan
* zones of the lung
* gas exchange
* pulmonary gas pressures
* alveolar gas equation
* alveolar–arterial gradient
* hemoglobin
* oxygen–hemoglobin dissociation curve (Oxygen saturation
* 2,3-BPG
* Bohr effect
* Haldane effect)
* carbonic anhydrase (chloride shift)
* oxyhemoglobin
* respiratory quotient
* arterial blood gas
* diffusion capacity (DLCO)

Insufficiency|

* high altitude
* death zone
* oxygen toxicity
* hypoxia

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