Acough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles andmicrobes. As a protectivereflex, coughing can be repetitive with thecough reflex following three phases: aninhalation, a forcedexhalation against a closedglottis, and a violent release of air from the lungs following opening of the glottis, usually accompanied by a distinctive sound.[1] Coughing into one's elbow or toward the ground—rather than forward at breathing height—can reduce the spread of infectious droplets in the air.[2]
Treatment should target the cause; for example,smoking cessation or discontinuing ACE inhibitors.Cough suppressants such ascodeine ordextromethorphan are frequently prescribed, but are not recommended for children. Other treatment options may target airwayinflammation or maypromote mucus expectoration. As it is a natural protective reflex, suppressing the cough reflex might have damaging effects, especially if the cough is productive (producingphlegm).[4]
Shadowgraph videos of the outer airflow during a cough, comparing unmasked coughing with several methods of covering one's mouth and nose: coughing into a fist, a cupped hand, a tissue, a "coughcatcher" device, asurgical mask, and anN95 mask
A cough in children may be either a normal physiological reflex or due to an underlying cause.[6] In healthy children it may be normal in the absence of any disease to cough ten times a day.[6] The most common cause of an acute or subacute cough is a viralrespiratory tract infection.[6] A healthy adult also coughs 18.6 times a day on average, but in the population with respiratory disease the geometric mean frequency is 275 times a day.[7] In adults with a chronic cough, i.e. a cough longer than 8 weeks, more than 90% of cases are due topost-nasal drip,asthma,eosinophilic bronchitis, andgastroesophageal reflux disease.[6] The causes of chronic cough are similar in children with the addition ofbacterial bronchitis.[6]
A cough can be the result of arespiratory tract infection such as thecommon cold,COVID-19,acute bronchitis,pneumonia,pertussis, ortuberculosis. In the vast majority of cases, acute coughs, i.e. coughs shorter than 3 weeks, are due to the common cold.[8] In people with a normal chest X-ray, tuberculosis is a rare finding. Pertussis is increasingly being recognised as a cause of troublesome coughing in adults.
After a respiratory tract infection has cleared, the person may be left with apostinfectious cough. This typically is a dry, non-productive cough that produces nophlegm. Symptoms may include a tightness in the chest, and a tickle in the throat. This cough may often persist for weeks after an illness. The cause of the cough may be inflammation similar to that observed in repetitive stress disorders such ascarpal tunnel syndrome. The repetition of coughing produces inflammation which produces discomfort, which in turn produces more coughing.[9] Postinfectious cough typically does not respond to conventional cough treatments. Medication used for postinfectious coughs may includeipratropium[9] to treat the inflammation, as well as cough suppressants to reduce frequency of the cough until inflammation clears.[10] Inflammation may increase sensitivity to other existing issues such asallergies, and treatment of other causes of coughs (such as use of an air purifier or allergy medicines) may help speed recovery.[11]
Asthma is a common cause of chronic cough in adults and children. Coughing may be the only symptom the person has from their asthma, or asthma symptoms may also include wheezing, shortness of breath, and a tight feeling in their chest. Depending on how severe the asthma is, it can be treated with bronchodilators (medicine which causes the airways to open up) or inhaled steroids. Treatment of the asthma should make the cough go away.
Chronic bronchitis is defined clinically as a persistent cough that produces sputum (phlegm) and mucus, for at least three months in two consecutive years. Chronic bronchitis is often the cause of "smoker's cough". The tobacco smoke causes inflammation, secretion of mucus into the airway, and difficulty clearing that mucus out of the airways. Coughing helps clear those secretions out. May be treated by quitting smoking. May also be caused bypneumoconiosis and long-term fume inhalation.
In people with unexplained cough,gastroesophageal reflux disease should be considered.[6] This occurs when acidic contents of the stomach come back up into the esophagus. Symptoms usually associated withGERD include heartburn, sour taste in the mouth, or a feeling of acid reflux in the chest, although, more than half of the people with cough from GERD do not have any other symptoms. An esophageal pH monitor can confirm the diagnosis of GERD. Sometimes GERD can complicate respiratory ailments related to cough, such as asthma or bronchitis. The treatment involves anti-acid medications and lifestyle changes with surgery indicated in cases not manageable with conservative measures.
Coughing may be caused byair pollution includingtobacco smoke, particulate matter, irritant gases, and dampness in a home.[6]The human health effects of poor air quality are far reaching, but principally affect the body's respiratory system and the cardiovascular system. Individual reactions to air pollutants depend on the type of pollutant a person is exposed to, the degree of exposure, the individual's health status and genetics. People who exercise outdoors on hot, smoggy days, for example, increase their exposure to pollutants in the air.
Aforeign body can sometimes be suspected, for example if the cough started suddenly when the patient was eating. Rarely, sutures left behind inside the airway branches can cause coughing. A cough can be triggered by dryness frommouth breathing or recurrent aspiration of food into thewindpipe in people withswallowing difficulties.[13][14]
Drugs used for treatments other than coughs, such asACE inhibitors which are often used to treathigh blood pressure, can sometimes cause cough as a side effect, and stopping their use will stop the cough.[15] Beta blockers similarly cause cough as an adverse event.[3]
Ahabit cough is one that responds to behavioral or psychiatric therapy after organic causes have been excluded. Absence of the cough during sleep is common, but not diagnostic. A tic cough is thought to be more common in children than in adults.[16]
Some cases of chronic cough may be attributed to a sensory neuropathic disorder.[17] Treatment for neurogenic cough may include the use of certain neuralgia medications. Coughing may occur intic disorders such asTourette syndrome, although it should be distinguished from throat-clearing in this disorder.
Given its irritant nature to mammal tissues,capsaicin is widely used to determine the cough threshold and as a tussive stimulant in clinical research of cough suppressants. Capsaicin is what makeschili peppers spicy, and might explain why workers in factories with these fruits can develop a cough.
Coughing may also be used for social reasons, and as such is not always involuntary. A voluntary cough, often written as "ahem", can be used to attract attention or express displeasure, as a form ofnonverbal,paralingualmetacommunication.[21][22]
A cough is a protectivereflex in healthy individuals which is influenced bypsychological factors.[6] The cough reflex is initiated by stimulation of two different classes ofafferent nerves, namely themyelinated rapidly adapting receptors, and nonmyelinatedC-fibers with endings in thelung.[23]
The type of cough may help in the diagnosis. For instance, an inspiratory "whooping" sound on coughing almost doubles the likelihood that the illness ispertussis.
A cough can be classified by its duration, character, quality, and timing.[6] The duration can be eitheracute (of sudden onset) if it is present less than three weeks,subacute if it is present between three or eight weeks, andchronic when lasting longer than eight weeks.[6] A cough can be non-productive (dry) or productive (whenphlegm is produced that may be coughed up assputum). It may occur only at night (then callednocturnal cough), during both night and day, or just during the day.[6]
A number of characteristic coughs exist. While these have not been found to be diagnostically useful in adults, they are of use in children.[6] A barky cough is part of the common presentation ofcroup.[25] A staccato cough has been classically described withneonatalchlamydialpneumonia.[26]
This sectionis missing information about treatment in adults. Please expand the section to include this information. Further details may exist on thetalk page.(December 2018)
The treatment of a cough in children is based on the underlying cause. In children half of cases go away without treatment in 10 days and 90% in 25 days.[27]
According to theAmerican Academy of Pediatrics the use ofcough medicine to relieve cough symptoms is supported by little evidence and thus not recommended for treating cough symptoms in children.[6] There is tentative evidence that the use of honey is better than no treatment ordiphenhydramine in decreasing coughing.[28] It does not alleviate coughing to the same extent asdextromethorphan but it shortens the cough duration better than placebo andsalbutamol.[28] A trial ofantibiotics orinhaled corticosteroids may be tried in children with a chronic cough in an attempt to treatprotracted bacterial bronchitis orasthma respectively.[6] There is insufficient evidence to recommend treating children who have a cough that is not related to a specific condition with inhaled anti-cholinergics.[29]
Because coughing can spread disease through infectious aerosol droplets, it is recommended to cover one's mouth and nose with the forearm, the inside of the elbow, a tissue or a handkerchief while coughing.[30]
For cough relief, adults may take cough suppresants such asdextromethorphan.[31]
Other common cough treatments include expectorants, decongestants, and antihistamines.[32][33]
Marine mammals such asdolphins andwhales cannot cough.[34] Someinvertebrates such asinsects andspiders cannot cough or sneeze.Crocodiles can cough.[35] Domestic animals and vertebrates such asdogs andcats can cough, because of diseases, allergies, dust or choking.[36] In particular, cats are known for coughing before spitting up ahairball.[36]
In other domestic animals,horses can cough because of infections, or due to poor ventilation and dust in enclosed spaces.[37]Kennel cough indogs can result from a viral or bacterial infection.
Deer can cough similarly to humans as a result of respiratory tract infections, such as parasitic bronchitis caused by a species ofDictyocaulus.[38]
^abFarzan, Sattar (1990), Walker, H. Kenneth; Hall, W. Dallas; Hurst, J. Willis (eds.),"Cough and Sputum Production",Clinical Methods: The History, Physical, and Laboratory Examinations (3rd ed.), Boston: Butterworths,ISBN978-0-409-90077-4,PMID21250200, retrieved2025-04-10
^"C.Chronic Cough". Archived fromthe original on 2010-10-01. Retrieved2010-10-10. National Lung Health Education Program > C. Chronic Cough] The Snowdrift Pulmonary Foundation, Inc. 2000.ISBN0-9671809-2-9
^Pyziel, Anna M.; Laskowski, Zdzisław; Demiaszkiewicz, Aleksander W.; Höglund, Johan (2017). "Interrelationships ofDictyocaulusspp. In Wild Ruminants with Morphological Description ofDictyocaulus cervin. Sp. (Nematoda: Trichostrongyloidea) from Red Deer,Cervus elaphus".Journal of Parasitology.103 (5):506–518.doi:10.1645/16-75.PMID28585897.S2CID25720548.
