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Last reviewed: 11.04.2020

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Coughing (Latin tussis) is an arbitrary or involuntary (reflex), jerky, forced, sonorous exhalation that occurs when mucus accumulates in the respiratory tract, inhaling irritating gaseous substances, or ingesting foreign particles into the trachea or bronchi. The purpose of the reflex is to clean the airways with the help of a strong and sharp exhalation.

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Mechanism of cough development

Cough occurs in response to irritation of cough receptors located in the larynx, the mucous membrane of various parts of the respiratory tract, but primarily - the trachea and bronchi (especially in the tracheal bifurcation zone, the branches of the bronchi), as well as the pleura. The irritation of the cough receptors causes a deep breath, after which the vocal chasm closes and strains the respiratory muscles and abdominal muscles, which creates a high positive intrathoracic pressure and, consequently, high airway pressure. In this case, the posterior membrane of the trachea flexes into its lumen. Then the voice gap opens sharply, and the pressure difference leads to the creation of a stream of air, whose velocity at different levels of the bronchial tree can vary from 0.5 to 50-120 m / sec (hurricane speed). The air flow of this force helps to remove mucus and foreign bodies.

The causes of cough are as follows: irritation of cough receptors cause mechanical, chemical and thermal effects, as well as inflammatory changes, especially of the respiratory tract, including those developing under the influence of the above factors.

So, if the frequency of coughing in a child every 3 minutes, and the cough itself has a whistling tone - this is characteristic of whooping cough. The peculiarity of coughing with pertussis consists in a number of short exhalations that last for several minutes and are interrupted from time to time by a whistling breath; it also happens that a number of these exhalation movements, which constitutes the actual coughing attack, can last from 2-3 minutes or more. The frequency of coughing in a child every 3 minutes sometimes also indicates an allergy or bronchial asthma, especially if there are family cases of allergic diseases.

Inflammation leads to irritation of cough receptors due to edema, hyperemia, exudation with the allocation of a wide range of biologically active substances, as well as secretions of the cells of the mucosa, mucus, blood, pus, which are the most frequent factors of irritation of cough receptors in the lumen of the respiratory tract. Inflammation sometimes affects both the respiratory tract (larynx, trachea, bronchi, bronchioles), and alveoli (for example, pneumonia, lung abscess).

  • Mechanical irritants - dust and other small particles, as well as violation of airway patency due to compression and increase the tone smooth muscle cells of their walls.
    • Tumors of the mediastinum, lungs, enlarged lymph nodes of the mediastinum, aneurysm of the aorta, endobronchial tumors cause compression of the bronchi and trachea from the outside, leading to the appearance of coughing.
    • A significant increase in the left atrium (usually associated with heart disease) leads to irritation of the recurrent laryngeal nerve.
    • Mechanical irritation also has a reduction in smooth muscle cells of the trachea and bronchi, for example, with an attack of bronchial asthma.
    • To the mechanical irritation of the larynx and trachea may result in an enlarged thyroid gland.
  • Chemical irritants - the inhalation of various substances with a strong odor, including cigarette smoke and a too intense smell of perfume. In addition, chemical irritation is possible with reflux-esophagitis, when the contents of the stomach enter the larynx and trachea (aspiration).
  • Thermal irritation - coughing occurs when breathing very cold and very hot air.

In connection with the great variety of pathological conditions accompanied by coughing, the question arises of differentiating different types of this feature. To do this, evaluate its productivity, appearance time and duration, volume and timbre, dependence on food intake, physical, psychoemotional loads and other provoking factors.

Correctly collected anamnesis in many cases allows you to put the correct preliminary diagnosis. When collecting anamnesis, it is advisable to stop at some points. It should be:

  • to determine what the debut of the disease is related to (whether it was ARD, contact with a pollutant or a potential allergen);
  • determine the duration of coughing, its frequency (sometimes it is constant, for example, with inflammation of the larynx, bronchogenic cancer, with metastases in the lymph nodes of the mediastinum, with some forms of tuberculosis, but more often it bothers periodically);
  • to establish the presence of concomitant symptoms (fever, discharge from the nose, itchy eyelids, asthma attacks, episodes of "wheezing" breathing, heartburn or belching, leg swelling, etc.);
  • to determine the presence of sputum, its nature;
  • To find out whether seasonal exacerbations are characteristic:
  • to find out whether the patient smokes, and whether there is an effect of professionally harmful factors, unfavorable environmental factors;
  • to find out whether the patient is taking drugs from the ACE inhibitor group. Reflex coughing usually happens paroxysmal dry (before the attack there is a feeling of dryness and perspiration in the throat) and is not associated with the pathology of the bronchopulmonary system. A provocateur of it often acts transferred ORVI. Such coughing occurs more often in persons with labile nervous system, autonomic dysfunction, against stressful situations, with a decrease in mucus production in the upper respiratory tract (facilitated by emotional factors, smoking, dry air, hyperventilation). In such patients, one can identify a long palatine tongue, hypertrophy of palatine tonsils, gastroesophageal reflux.

Tracheobronchial dyskinesia manifests itself with a stubborn, dry, barking cough. Often this is characterized as a paroxysmal tubal cough: it occurs with physical exertion, laughter, against the background of the common cold, may increase in the abdominal position, accompanied by inspiratory dyspnea, when an attempted forced exhalation intensifies the symptoms. Can be combined with bronchial asthma and other diseases.


Epidemiological studies that investigate the incidence of cough, regardless of the nature of the disease, are not carried out. However, up to 25% of patients seeking medical help suffer from respiratory diseases; in most such cases, one of the symptoms of the disease is coughing. Since there are about 50 causes of coughing, it can be said about the high incidence of this symptom.

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Cough is usually considered acute if it lasts less than 3 weeks and is chronic if it worries the patient for more than 3 weeks. However, this division is relatively, For example, cough with exacerbation of chronic bronchitis with adequate treatment can last less than 3 weeks.

Distinguish also dry (without separation of sputum) and moist (with sputum discharge of a different nature).

In accordance with the clinical characteristics of:

  • bitonal (in the sound of two tones - low and extra high), is observed as a sign of compression of the trachea and large bronchi:
  • barking (loud, jerky, dry), occurs when the larynx or trachea is affected, sometimes combined with hoarseness and aphonia;
  • convulsive (paroxysmal, with rapid successive shocks, interrupted by a noisy inspiration), may be with whooping cough;
  • spasmodic (persistent dry, with spasm of the larynx), occurs when the lower laryngeal nerve is irritated;
  • deafness occurs with severe emphysema;
  • soundless is observed with paralysis or destruction of vocal cords, with tracheostomy, lesions of the recurrent laryngeal nerve;
  • resonating, is observed in the presence of caverns and other pulmonary cavities in the lungs;
  • nasal (persistent, with pain in the throat).

The presence or absence of sputum is an important diagnostic feature. With such diseases as laryngitis, dry pleurisy, compression of the main bronchi with enlarged bifurcation lymph nodes (tuberculosis, lymphogranulomatosis, cancer metastases, etc.), coughing is dry. In some cases, it can be dry only at the onset of the disease (bronchitis, pneumonia, lung abscess, tuberculosis, bronchogenic cancer, etc.).

With bronhozkazah, abscess, cavernous tuberculosis, chronic bronchitis, the morning departure of sputum accumulated overnight in cavities and bronchi is noted. In the case of bronchiectasias, when they are located in the left lung, sputum goes away in position on the right side, and vice versa. If the bronchiectasis is in the anterior parts of the lungs, sputum is better left in the lying position on the back, and in the back - on the stomach.

Night coughing is observed, for example, with an increase in lymph nodes of the mediastinum (lymphogranulomatosis, tuberculosis, malignant neoplasms). In this case, the enlarged lymph nodes irritate the reflexogenic zone of the trachea bifurcation, and the cough reflex is most pronounced at night, during the period of an increase in the tone of the vagus nerve. With an increased tone of the vagus nerve, there are also night attacks of coughing in bronchial asthma.

You can detect blood in the sputum. Blood discharge with sputum, or hemoptysis, is most often observed with pulmonological disease (tumor, tuberculosis, pneumonia, abscess, bronchiectasis, mycoses, including actinomycosis, as well as influenza) and cardiovascular pathologies (heart defects, thrombosis or embolism vessels of the pulmonary artery). In addition, hemoptysis can be with hematological diseases, systemic autoimmune pathology and some other conditions.

There are complications of this sign, the most frequent of which are insomnia, hoarseness, sweating, pain in the muscles, bones, headache, urinary incontinence. When coughing, it is possible to increase inguinal and the development of diaphragmatic hernias. Serious complications are the development of secondary spontaneous pneumothorax and cough-and-fainting syndrome, formerly called betotopepsy syndrome (loss of consciousness, sometimes combined with seizures, at the height of a coughing fit).

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Types of cough

Depending on the above reasons, a non-productive and productive cough is distinguished. The productive is characterized by the separation of sputum. For some diseases, only non-productive cough is typical, for others, especially inflammatory pulmonological diseases, a productive, usually non-productive. In a number of cases (for example, with acute laryngitis) after the productive phase, the phase of an unproductive cough that results from the decrease in the sensitivity threshold of cough receptors is repeatedly noted. In the latter case, the pathogenetically justified the appointment of non-expectorants, and antitussive agents.

Dry cough

Unproductive cough - dry, paroxysmal, debilitating and not bringing relief - is characteristic for the early stages of acute bronchitis, pneumonia (especially viral), lung infarction, the initial period of asthma attack, pleurisy and pulmonary embolism. Dry coughing with acute bronchitis is often preceded by a feeling of tightness in the chest, difficulty breathing. Also, a similar symptom arises in response to the inhalation of substances irritating the mucous membrane or entering the lumen of the dronchus or trachea of the foreign body.

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Wet cough

The productive cough differs with sputum secretion.

Despite a strong cough push, the sputum can not be expectorated. This is usually due to its increased viscosity or arbitrary swallowing. Often, a minor cough and poor sputum is not considered a sign of the disease (for example, the usual morning cough with a smoker's bronchitis), so the doctor should himself focus on the patient's complaint on this complaint.

Who to contact?

Urgent measures for diagnosis and treatment

Usually cough as a monosymptom (without suffocation, loss of consciousness, acute pain and other conditions) does not require emergency diagnostic and therapeutic measures. An exception may be the ingress of foreign particles and irritating gases into the respiratory tract. In the obvious cases, it is necessary first of all to stop contact with the irritating gas and to ensure the inhalation of clean air, and in case of contact with a foreign body, remove it from the respiratory tract. In complicated or unclear cases, laryngoscopy or tracheobronchoscopy may be required.

Who should I contact if I have a cough?

If you suspect of an allergic cough, asthma, chronic obstructive armor, allergic and polyposis rhinosinusopathy, you need to consult an allergist.

Given the great diagnostic difficulties in diagnosing bronchial asthma with its "cough" variant, it should be remembered that chronic coughing in such patients can be the only symptom. It is usually dry, paroxysmal, nocturnal, in the afternoon, any manifestations of the disease may be absent (with auscultation, dry wheezing is not determined, and according to spirometry, bronchial obstruction is absent). The diagnosis is facilitated by the presence of eosinophilia in blood and sputum tests, which, in combination with the above clinical manifestations, is the basis for referring the patient to an allergist. In-depth examination usually reveals the hyperreactivity of the bronchi (according to bronchoprovocation tests), as well as a good response to anti-asthmatic treatment. There is also described "eosinophilic bronchitis" - a combination of coughing and severe eosinophilia induced sputum without signs of bronchial hyperreactivity. It also achieves a good therapeutic effect from the use of inhaled glucocorticoids. The final diagnosis can be made only after examination by an allergist.

Consultation otolaryngologist is necessary for aspiration, pathology of ENT organs (including reflex cough), asthma and chronic bronchitis. Consultation pulmonologist is necessary for interstitial lung diseases, chronic bronchitis, bronchiectasis, pleurisy, lung abscess. Consultation of a gastroenterologist with gastroesophageal reflux disease. Consultation of the thoracic surgeon - with bronchiectasis, an abscess of the lung.

Consultation of a cardiologist - if there is a suspicion of a cardiovascular cough genesis, phthisiatric consultation - if there is a suspicion of tuberculosis and sarcoidosis; Oncologist's consultation - if there is a suspicion of a tumor genesis, endocrinologist's consultation if there are signs of a pathology of the thyroid gland; consultation of the psychoneurologist - with suspicion of psychogenic cough.

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