Dry cough is a type of cough. In clinical practice, a productive wet cough is also distinguished, which is characterized by sputum production.
What diseases cause a dry cough?
For some diseases, only a dry cough is typical, for others, especially inflammatory diseases of the respiratory system, it is productive, usually followed by a non-productive one. In some cases (for example, in acute laryngitis), after the wet cough phase, a phase of non-productive cough is observed again, which occurs as a result of a decrease in the sensitivity threshold of cough receptors. In the latter case, when a dry cough dominates, the prescription of antitussives rather than expectorants is pathogenetically justified.
A dry cough, paroxysmal, debilitating and not bringing relief, is characteristic of:
- early stages of acute bronchitis,
- pneumonia (especially viral),
- pulmonary infarction,
- the initial period of an attack of bronchial asthma,
- pleurisy;
- pulmonary embolism.
A dry cough in acute bronchitis is often preceded by a feeling of tightness in the chest and difficulty breathing. Also, a similar dry cough occurs in response to the inhalation of substances that irritate the mucous membrane or the entry of a foreign body into the lumen of the respiratory tract.
- A dry cough – not paroxysmal, prolonged, painful – is usually observed with:
- endobronchial tumor growth;
- compression of a large bronchus or trachea from the outside (for example, enlarged lymph nodes of the mediastinum);
- pulmonary fibrosis;
- congestive heart failure.
- In extreme cases, inhalation between a series of coughing impulses may resemble stridor – a whistling noise with difficulty breathing due to a sharp narrowing of the lumen of the larynx, trachea or bronchi.
- Against the background of suffocation, it is characteristic of cardiac asthma (interstitial pulmonary edema) and is characterized by the sudden onset of a non-productive cough: as the edema progresses to the alveolar stage, the dry cough becomes productive – foamy pink sputum begins to be released.
- If the coughing attack drags on, you can observe swelling of the veins of the neck, the appearance of cyanosis of the face and neck (stagnation of venous blood due to increased intrathoracic pressure and difficulty in outflow).
- Whooping cough is a paroxysmal, convulsive dry cough.
Sometimes a dry cough is accompanied by pain, which becomes severe when the pleura is involved, especially with a deep breath, which usually ends a coughing attack.
How can a dry cough be complicated?
Prolonged paroxysmal dry cough can be complicated by pneumomediastinum (break of air into the mediastinum with subsequent development of subcutaneous emphysema) and pneumothorax (penetration of air into the pleural cavity due to tearing of the visceral or parietal layer of the pleura). In this case, a dry cough is fraught with the formation of valvular pneumothorax, when during the next inhalation, part of the air enters the pleural cavity, increasing compression atelectasis of the lung.