Cough is the most frequent breathing symptom, a complex mechanism which helps in protecting the respiratory system.

Cough is in fact a defense mechanism that has the purpose keep the airways free from secretions, mucus, phlegm and irritants like smoke, dust etc. It occurs due to the irritation of specific receptors located in the larynx, trachea and bronchial tube. Basically we talk about acute cough if it has recently arisen and if it is linked to infectious forms of the respiratory tract (colds, acute laryngitis, acute tracheitis, acute bronchitis), while it is called chronic cough if arising from long time and resistant to symptomatic treatments.

When coughing is accompanied by other symptoms, it is easier to attribute the cause to a specific disease: e.g. in association with normal sputum is the clinical picture of chronic bronchitis; when it is associated with breathlessness with wheezing it could be asthma; when it occurs acutely in association with fever and respiratory distress may indicate the presence of bronchopneumonia. Therefore, it is necessary to consider all the other symptoms present simultaneously and correlate with the results of the chest x-ray and pulmonary function tests.

Common causes of chronic cough are mainly chronic respiratory disease: outbreaks of pneumonia, chronic bronchitis, allergies and so on. You can also distinguish between "dry cough" (caused, for example, by irritation from smoking or excessive dryness of the air),"productive cough" (if you expel mucus), "convulsive cough" (eg. when provoked by the presence of a foreign body into the trachea), "nervous cough" (not due to an involvement of the respiratory tract).

If the problem persists for a long time (weeks) will never be ignored and will require the assessment of the doctor in order to rule out that this is a symptom of serious illness on heart or lungs. As cough is a defense mechanism, should not be inhibited, but when the symptom is presented particularly painful, special measures that mitigate the entity could be followed:
drink a lot and often in order to rehydrate the upper respiratory tract, reducing the state of anger and getting an emollient effect on the secretion
humidify locations and avoid excessive heat
avoid smoking and reside in areas with stagnant cigarette smoke

It will still be important to limit the use of drugs (sedatives or expectorants) medical advice or pharmacist without abusing it. In fact, especially with regard to sedative drugs, excessive use may delay a diagnosis important or slow down the ejection mechanism of secretions and any microbes contained in them.