Bronchitis: symptoms, causes and treatment

By Cristiano Antonino On Feb 21, 2023

Bronchitis is one of the most common diseases of the respiratory system. It is the inflammatory process of the mucous membrane lining the bronchi, the tree-like structures that transport air to and from the lungs

The bronchi originate from the bifurcation of the trachea into two main areas, one destined for the right lung and the other for the left lung.

The bronchi then branch into smaller and smaller ducts within the lungs to the so-called bronchioles.

The bronchi perform an essential function for the respiratory process

In inspiration, air, through the nose, pharynx, trachea and bronchi, reaches the pulmonary alveoli where the exchange of the gases it contains (mainly oxygen) with the capillaries surrounding the alveoli takes place.

On exhalation, the air, poor in oxygen and enriched with carbon dioxide, takes the same route back.

The inner walls of the bronchi play a protective role as they produce mucus to imprison dust and other potentially irritating particles so that they cannot reach the lung.

When foreign particles make their way into the bronchi through inhaled air, they cause irritation of the entire region, resulting in higher than normal mucus production.

The excess mucus is then eliminated by coughing.

The most common symptoms of bronchitis are coughing, with or without mucus production (phlegm), difficulty breathing, wheezing and tightness in the chest.

Bronchitis can be of two distinct types:

acute, generally caused by a viral infection
chronic, due to airway damage caused by cigarette smoke or air pollutants

Typically in acute bronchitis, the inflammation is caused by a virus that has already affected the first airways, such as the larynx and trachea, and spreads to the bronchi.

Responsible for the infection can be

common viruses, such as cold or flu viruses
more difficult-to-treat viruses such as respiratory syncytial virus or adenovirus. The most significant symptom in this case is difficulty breathing, which results in wheezing, shortness of breath, coughing, sleep disturbances and chest tightness.

The main symptoms of acute bronchitis are

cough
production of phlegm (sputum)
difficulty breathing
weakness
in addition to the complaints generated by a cold or flu. Symptoms commonly disappear spontaneously over the course of 2-3 weeks.

Chronic bronchitis is an inflammation of the bronchi that persists over time, making them constantly irritated.

It is therefore a more serious condition than the acute form, causing persistent coughing and phlegm for at least 2-3 months and reoccurring annually.

The most common symptoms of chronic bronchitis are

excessive mucus production
cough
breathing difficulties

It should also be noted that the treatment of chronic bronchitis is useful in alleviating its symptoms but not sufficient to cure it if the sources of bronchial irritation (especially smoking) are not simultaneously eliminated.

As already mentioned, acute bronchitis is commonly of viral origin.

It is mainly generated by the same viruses responsible for colds or influenza.

Viruses are transmitted by air (saliva droplets, emitted by coughing, remain suspended in the air) or by touching the nose and mouth with unhygienic hands.

More rarely, the acute form is generated by bacteria.

Bacterial bronchitis is more likely to develop in the event of an epidemic, i.e. when many people are affected at the same time in the same region.

In most cases, people with acute bronchitis improve within a few days (although the cough may persist for several weeks).

Chronic bronchitis is typically caused by long-term exposure to irritants such as cigarette smoke (active or passive), air pollutants and toxic substances.

When bronchitis is chronic

The chronic form is a serious condition that can last over time and lead to a progressive disease (with worsening trends over time), called chronic obstructive bronchitis or chronic obstructive pulmonary disease (COPD), and respiratory failure.

Elimination of active and passive smoking can improve or even resolve chronic bronchitis.

Bronchial constriction, attributable to asthma, is often associated with bronchitis and may lead to coughing.

In those who report this condition, spirometry results are normal if the bronchial constriction is contained or circumscribed.

There is also a form of chronic obstructive pulmonary disease represented by so-called bronchiectasis, i.e. irreversible dilatations of the bronchi (in certain cases inherited from pneumonia experienced in childhood).

They give rise to real reservoirs of mucus, generating the risk of bacterial colonisation and thus new infections that can in turn produce further damage to the airways themselves.

Diseases can develop in the lungs that begin with just an irritative cough and then, over time, generate wheezing during minor exertion.

One example is interstitiopathy, a disease generated by the hardening of the lattice that supports the innumerable lung alveoli (the acini in which we absorb oxygen). In this case, the reason for the cough can be investigated through a chest CT scan.

Extra-respiratory causes of bronchitis

There are also extrarespiratory causes that, if not identified and appropriately treated, can prolong bronchitis or induce episodes of recurrence.

One example is gastro-oesophageal reflux, sometimes facilitated by the rise of gastric juices at the mouth of the stomach due to the presence of a hiatal hernia.

In such cases, a chest X-ray, ENT examination or gastroenterologist intervention, up to gastroscopy, may be recommended.

If blood tests reveal certain immunological irregularities, a chronic obstruction of the nose should be sought as a predisposing condition for recurrent bronchitis.

Other factors that facilitate the occurrence of persistent bronchitis may be

a chronic anaemia
hypothyroidism, i.e. insufficient thyroid activity
a diet lacking in protein for a long time.

The treatment of bronchitis varies depending on whether one has acute or chronic bronchitis

The former, which is viral in origin, generally heals spontaneously within a few days; it is sufficient to rest and take fluids, resort, when necessary, to anti-inflammatories, antipyretics and mucolytics to relieve the symptoms.

If, after a few days, there is still a fever of over 38°, breathing difficulties, production of greenish mucus or with traces of blood, or if the cough persists for more than three weeks, it is advisable to contact your doctor for further investigation and correct treatment.

As far as chronic bronchitis is concerned, there is no decisive cure (unless the underlying causes are also eliminated), but certain drugs such as mucolytics to eliminate mucus, bronchodilators and corticosteroids to reduce inflammation can be used to alleviate the symptoms.

What is instead important in the chronic form of bronchitis is to change certain habits that are responsible for the constant irritation of the bronchi, i.e. stopping smoking and avoiding exposure to pollutants, so as not to worsen or in some cases resolve the disorder.

Acute bronchitis is a disease of viral origin so antibiotics should not be prescribed by a doctor as they are unable to fight the virus.