Respiratory discomfort can be caused by viral, bacterial, allergic, non-allergic and non-infectious factors, as well as environmental or inflammatory causes.
When respiratory wellbeing takes a turn for the worse, the first instinct is often to look for the cause. In fact, respiratory discomfort can stem from a wide variety of causes, ranging from a simple seasonal virus to a reaction to a polluted working environment.
Viral causes : colds, flu, coronaviruses and adenoviruses fall into this category (3). These viruses mainly affect the upper respiratory tract (nose, sinuses, pharynx, larynx, middle ear), but can also reach the lower respiratory tract (the part of the larynx below the vocal cords, trachea, bronchi, bronchioles and lungs).
Bacterial origin : associated with pneumonia, this generally involves microorganisms such as Streptococcus pneumoniae or Mycoplasma pneumoniae . It can also occur as a secondary infection following a viral infection (3).
Allergic aetiology : this most commonly involves allergic rhinitis and allergic asthma. This is an immunological reaction to airborne allergens: pollen, house dust mites, mould and animal dander (3). Respiratory symptoms of allergic origin are sometimes seasonal, as in the case of hay fever.
Non-allergic and non-infectious causes: the medical literature reports cases of hormonal, drug-induced, gustatory or vasomotor rhinitis. There is also a syndrome known as non-allergic rhinitis with eosinophilia (NARES) (3).
Environmental causes: dust, tobacco smoke and air pollutants, to name but a few, can irritate the airways and cause chronic symptoms (3).
Inflammatory causes : respiratory discomfort stems from bronchial obstruction, inflammation of the airways or excessive mucus production (3).
