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Related to cough: bronchitis, whooping cough, dry cough




A cough is a forceful release of air from the lungs that can be heard. Coughing protects the respiratory system by clearing it of irritants and secretions.


While people can generally cough voluntarily, a cough is usually a reflex triggered when an irritant stimulates one or more of the cough receptors found at different points in the respiratory system. These receptors then send a message to the cough center in the brain, which in turn tells the body to cough. A cough begins with a deep breath in, at which point the opening between the vocal cords at the upper part of the larynx (glottis) shuts, trapping the air in the lungs. As the diaphragm and other muscles involved in breathing press against the lungs, the glottis suddenly opens, producing an explosive outflow of air at speeds greater than 100 mi (160 km) per hour.
In normal situations, most people cough once or twice an hour during the day to clear the airway of irritants. However, when the level of irritants in the air is high or when the respiratory system becomes infected, coughing may become frequent and prolonged. It may interfere with exercise or sleep, and it may also cause distress if accompanied by dizziness, chest pain, or breathlessness. In the majority cases, frequent coughing lasts one to two weeks and tapers off as the irritant or infection subsides. If a cough lasts more than three weeks it is considered a chronic cough, and physicians will try to determine a cause beyond an acute infection or irritant.
Coughs are generally described as either dry or productive. A dry cough does not bring up a mixture of mucus, irritants, and other substances from the lungs (sputum), while a productive cough does. In the case of a bacterial infection, the sputum brought up in a productive cough may be greenish, gray, or brown. In the case of an allergy or viral infection it may be clear or white. In the most serious conditions, the sputum may contain blood.

Causes and symptoms

In the majority of cases, coughs are caused by respiratory infections, including:
  • colds or influenza, the most common causes of coughs
  • bronchitis, an inflammation of the mucous membranes of the bronchial tubes
  • croup, a viral inflammation of the larynx, windpipe, and bronchial passages that produces a bark-like cough in children
  • whooping cough, a bacterial infection accompanied by the high-pitched cough for which it is named
  • pneumonia, a potentially serious bacterial infection that produces discolored or bloody mucus
  • tuberculosis, another serious bacterial infection that produces bloody sputum
  • fungal infections, such as aspergillosis, histoplasmosis, and cryptococcoses
Environmental pollutants, such as cigarette smoke, dust, or smog, can also cause a cough. In the case of cigarette smokers, the nicotine present in the smoke paralyzes the hairs (cilia) that regularly flush mucus from the respiratory system. The mucus then builds up, forcing the body to remove it by coughing. Post-nasal drip, the irritating trickle of mucus from the nasal passages into the throat caused by allergies or sinusitis, can also result in a cough. Some chronic conditions, such as asthma, chronic bronchitis, emphysema, and cystic fibrosis, are characterized in part by a cough. A condition in which stomach acid backs up into the esophagus (gastroesophageal reflux) can cause coughing, especially when a person is lying down. A cough can also be a side-effect of medications that are administered via an inhaler. It can also be a side-effect of beta-blockers and ACE inhibitors, which are drugs used for treating high blood pressure.


To determine the cause of a cough, a physician should take an exact medical history and perform an exam. Information regarding the duration of the cough, other symptoms may accompanying it, and environmental factors that may influence it aid the doctor in his or her diagnosis. The appearance of the sputum will also help determine what type of infection, if any, may be involved. The doctor may even observe the sputum microscopically for the presence of bacteria and white blood cells. Chest x rays may help indicate the presence and extent of such infections as pneumonia or tuberculosis. If these actions are not enough to determine the cause of the cough, a bronchoscopy or laryngoscopy may be ordered. These tests use slender tubular instruments to inspect the interior of the bronchi and larynx.


Treatment of a cough generally involves addressing the condition causing it. An acute infection such as pneumonia may require antibiotics, an asthma-induced cough may be treated with the use of bronchodialators, or an antihistamine may be administered in the case of an allergy. Physicians prefer not to suppress a productive cough, since it aids the body in clearing the respiratory system of infective agents and irritants. However, cough medicines may be given if the patient cannot rest because of the cough or if the cough is not productive, as is the case with most coughs associated with colds or flu. The two types of drugs used to treat coughs are antitussives and expectorants.


Antitussives are drugs that suppress a cough. Narcotics—primarily codeine—are used as antitussives and work by depressing the cough center in the brain. However, they can cause such side effects as drowsiness, nausea, and constipation. Dextromethorphan, the primary ingredient in many over-the-counter cough remedies, also depresses the brain's cough center, but without the side effects associated with narcotics. Demulcents relieve coughing by coating irritated passageways.


Expectorants are drugs that make mucus easier to cough up by thinning it. Guaifenesin and terpin hydrate are the primary ingredients in most over-the-counter expectorants. However, some studies have shown that in acute infections, simply increasing fluid intake has the same thinning effect as taking expectorants.

Alternative treatment

Coughs due to bacterial or viral upper respiratory infections may be effectively treated with botanical and homeopathic therapies. The choice of remedy will vary and be specific to the type of cough the patient has. Some combination over-the-counter herbal and homeopathic cough formulas can be very effective for cough relief. Lingering coughs or coughing up blood should be treated by a trained practitioner.
Many health practitioners advise increasing fluids and breathing in warm, humidified air as ways of loosening chest congestion. Others recommend hot tea flavored with honey as a temporary home remedy for coughs caused by colds or flu. Various vitamins, such as vitamin C, may be helpful in preventing or treating conditions (including colds and flu) that lead to coughs. Avoiding mucous-producing foods can be effective in healing a cough condition. These mucous-producing foods can vary, based on individual intolerance, but dairy products are a major mucous-producing food for most people.


Because the majority of coughs are related to the common cold or influenza, most will end in seven to 21 days. The outcome of coughs due to a more serious underlying disease depends on the pathology of that disease.


It is important to identify and treat the underlying disease and origin of the cough. Avoiding smoking and direct contact with people experiencing cold or flu symptoms is recommended. Washing hands frequently during episodes of upper-respiratory illnesses is advised. Parents should follow recommended vaccination schedules for pertussion (whooping cough) to help prevent the disease from occurring.

Key terms

Antitussives — Drugs used to suppress coughing.
Expectorant — Drug used to thin mucus.
Gastroesophageal reflux — Condition in which stomach acid backs up into the esophagus.
Glottis — The opening between the vocal cords at the upper part of the larynx.
Larynx — A part of the respiratory tract between the pharynx and the trachea, having walls of cartilage and muscle and containing the vocal cords.
Sputum — The mixture of mucus, irritants, and other substances expelled from the lungs by coughing.



"Whooping Cough on the Rise." Consumer Reports May 2004: 51.


National Heart, Lung and Blood Institute. PO Box 30105, Bethesda, MD 20824-0105. (301) 251-1222.


1. a sudden noisy expulsion of air from the lungs; called also tussis.
2. to produce such an expulsion of air.
dry cough cough without expectoration.
productive cough cough attended with expectoration of material from the bronchi.
reflex cough a cough due to the irritation of some remote organ.
wet cough productive cough.
whooping cough see whooping cough.


1. A sudden explosive forcing of air through the glottis, occurring immediately on opening the previously closed glottis, excited by mechanical or chemical irritation of the trachea or bronchi or by pressure from adjacent structures.
2. To force air through the glottis by a series of expiratory efforts.


1. sudden noisy expulsion of air from lungs.
2. to produce such an expulsion.

dry cough  cough without expectoration.
hacking cough  a short, frequent, shallow and feeble cough.
productive cough  cough with expectoration of material from the bronchi.
reflex cough  cough due to irritation of some remote organ.
wet cough  productive c.
whooping cough  pertussis.


(kôf, kŏf)
v. coughed, coughing, coughs
To expel air from the lungs suddenly and noisily, often to keep the respiratory passages free of irritating material.
To expel by coughing: coughed up phlegm.
1. The act of coughing.
2. An illness marked by frequent coughing.


Etymology: AS, cohhetan
a sudden audible expulsion of air from the lungs. Coughing is preceded by inspiration, the glottis is partially closed, and the accessory muscles of expiration contract to expel the air forcibly from the respiratory passages. Coughing is an essential protective response that serves to clear the lungs, bronchi, and trachea of irritants and secretions or to prevent aspiration of foreign material into the lungs. It is a common symptom of diseases of the chest and larynx. Chronic coughing may be indicative of tuberculosis, lung cancer, bronchiectasis, asthma, or bronchitis. Otitis media, allergies, subdiaphragmatic irritation, congestive heart failure, and mitral valve disease may be associated with episodes of severe chronic coughing. Coughing is a reflex action that may be induced voluntarily and, to some extent, voluntarily inhibited. The cough-reflex center is located in the medulla of the brain. It responds to stimulation transmitted by the glossopharyngeal (CN9) or vagus (CN10) nerve. The reflex is initiated by chemical or mechanical irritation of the pharynx, larynx, or tracheobronchial tree. Because the function of coughing is to clear the respiratory tract of secretions, it is important that the cough expel accumulated debris. If it does not because of, for example, weakness or inhibition by pain, instruction in effective coughing and deep-breathing exercises is helpful. Persons with chronic coughs may obtain symptomatic relief through environmental controls that reduce irritants in and humidify air. Medication may help dilate the bronchi, liquefy secretions, and increase expectoration. Antitussive medications are sometimes prescribed even in the absence of mucus or congestion. When congestion is present and the patient is unable to cough up the mucus, an expectorant may be prescribed.


noun A voluntary or involuntary explosive expulsion of air from the lungs verb To explosively expulse air from the lungs after previously halting same at the glottis. See Brassy cough, Whooping cough.


1. A sudden expulsion of air through the glottis, occurring immediately on opening the previously closed glottis, and excited by mechanical or chemical irritation of the trachea or bronchi, or by pressure from adjacent structures.
2. To force air through the glottis by a series of expiratory efforts.


A protective reflex by which a sudden blast of compressed air is released along the bronchial tubes and windpipe (trachea) and through the voice box (larynx). Coughing expels irritating and potentially infective or obstructive material. It is a sign of most respiratory infections and many respiratory disorders. Persistent (chronic) chest disorders feature regular coughing because of the production of excessive bronchial secretions. The quality of the cough may be diagnostic, as in WHOOPING COUGH (pertussis), partial obstruction of the larynx or paralysis of the nerves to the larynx, but is usually non-specific. It is often early in lung cancer and late in TUBERCULOSIS. Sputum may be scanty or, as in BRONCHIECTASIS, voluminous. It may contain blood (HAEMOPTYSIS).


n the expulsion of air forcefully and audibly from the lungs. A cough works to loosen and clear foreign matter and irritants from the air passages and is often a symptom of infection.


Sudden explosive forcing of air through the glottis, occurring immediately on opening the previously closed glottis, excited by irritation of the trachea or bronchi or by pressure from adjacent structures.


n a sudden, noisy expulsion of air from the lungs. See also mechanism, cough.
cough, gander,
n the characteristic clanging, brassy cough of tracheal obstruction.


1. a sudden noisy expulsion of air from the lungs.
2. to produce such an expulsion of air.

dry cough
cough without expectoration.
goose honk cough
a chronic, harsh, dry cough characteristic of collapsed trachea.
nocturnal cough
in dogs associated with heart disease, psychogenic coughing or collapsed trachea.
productive cough
cough attended with expectoration of material from the bronchi.
psychogenic cough
dogs sometimes associate coughing with the attention received and develop it as a habit.
cough reflex
1. the sequence of events initiated by the sensitivity of the lining of the passageways of the lung and mediated by the medulla as a consequence of impulses transmitted by the vagus nerve, resulting in coughing, i.e. the clearing of the passageways of foreign matter.
2. the response elicited by applying pressure on a trachea. Increased with inflammation of the respiratory epithelium; decreased by cough suppressants and pain.

Patient discussion about cough

Q. What Causes Cough With Fever? Often during winter I become sick with fever and on going cough. What causes it?

A. Cough with fever can be a first sign to many respiratory tract infections with viruses or bacterias, starting from simple ones as the common cold (or "flu") up to more serious conditions such as pneumonia, that requires medical care and medications.

Q. What Treats Cough With Fever? I have the flu and so my entire body hurts, and I can't stop coughing. What type of medications can I buy over-the-counter to help me feel better?

A. Simple analgesics are good for lowering fever and easing pain. As for the cough, there is a question whether or not cough suppressants are actually recommended.

Q. Addiction to a cough syrup?? Is it true you can get addicted to cough syrup? And is so- why is that? Is it dangerous? Should I not take cough syrup?

A. here is a story about an air force pilot who had an addiction to cough suppressant who ended bad and about the phenomenon in general:

More discussions about cough
References in periodicals archive ?
Your cough should improve over a few days, with mucus looking lighter and thinner, Bergquist said.
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2014), which is followed closely by a reflex cough response produced to protect the airway through active expulsion of foreign material.
And the conclusion ACS reached was: "There is very little evidence that cough syrup is effective at treating coughs.
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5 mg is better that placebo and as effective as lidocaine to prevent fentanyl induced cough.
The panel defined unexplained chronic cough as a cough that persists longer than 8 weeks, and that remains unexplained after evaluations and supervised therapeutic trials are conducted.
Here's a list of acute and chronic coughs you might encounter: CHESTY COUGH Causes: A chesty cough is caused by excessive mucus in the chest, produced to help clear the airways.
Have some water, tissues and cough medicine at hand to help soothe the cough.
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Chronic cough which is one of the frequent reasons for medical referal is defined as resistant cough lasting for longer than three weeks (1).