Asthma: what it is, symptoms, causes and risk factors, diagnosis, treatments

Asthma: what it is, symptoms, causes and risk factors, diagnosis, treatments

Asthma is a chronic inflammatory disease of the respiratory tract, one of the most common in the world. In detail, asthma is caused by the narrowing or obstruction, usually reversible, of the airways and bronchi.

Among the symptoms with which it occurs are: wheezing and wheezing, respiratory crises, cough and chest tightness.

However, asthma symptoms can be sporadic, but in any case with the presence of acute crises, or persistent, depending on the stage of the disease.

In any case, asthma is a pathology that can be treated and kept under control as long as you take the drugs prescribed by your doctor (costeroids and anti-inflammatories) and have regular checkups.

Furthermore, it is essential to avoid all those risk factors that can cause or worsen symptoms, such as exposure to allergens or other triggers.

Asthma: what is it?

The word asthma comes from the ancient Greek and means “to pant”, that is, to breathe with difficulty, which is precisely one of the symptoms of the disease.

To explain asthma, it is necessary to briefly explain our respiratory system.

The air you inhale through your nose and mouth travels through your larynx and then down your trachea to your lungs. These organs contain branches of the lower airways called bronchi (larger) and bronchioles (smaller).

In addition, the walls of the bronchi and bronchioles contain muscle fibers that can contract and change their size. Finally, they are covered with a thin layer of mucus which serves to retain harmful impurities in the air, including viruses and bacteria.

Thus, air normally enters the airways from the nose and mouth and arrives unhindered at the pulmonary alveoli. The latter are small elastic balloons located at the end of the bronchioles which have the function of exchanging the oxygen we breathe with the carbon dioxide we exhale.

However, in people with asthma, the walls of the airways are thickened and swollen by inflammation.

In addition, there is an increased production of mucus and all this hinders the passage of air. Added to this is the fact that the muscle cells surrounding the airways contract, narrowing them – due to the so-called bronchospasm – making the passage of air even more difficult.

In summary, asthma and the symptoms with which it manifests are the consequence of a narrowing of the diameter of the bronchi and bronchioles.

Asthma: history

This disease was already known in China in 2600 BC and was defined as a disorder characterized by noisy breathing.

Even the Babylonian Code of Hammurabi, around 1750 BC, spoke of symptoms related to shortness of breath. But the first to use the term “asthma” was Hippocrates, in 400 BC to describe the respiratory disorder. Furthermore, he is thought to have been the first to identify the relationship between the environment and disease, to the extent that many consider him the first allergist.

Instead, it was Alexander the Great who discovered, when he invaded India, that in this country they used the stramonium plant to relax the lungs. In fact, this herb is still used in inhalers today.

Finally, among the Romans, doctors described asthma as wheezing and the inability to breathe quietly, and Pliny the Elder noted that pollen could be a trigger.

While in South America, Incas and Aztecs used particular herbs to cure asthma, with the introduction of tobacco in Europe, which took place in 1500, this was used to induce cough and expectorate mucus.

The prime cure

But it was only in 1900 that the first truly effective treatments were tested. In the 1940s and 1950s, therapy consisted of:

  • Epinephrine (adrenaline) injections.
  • Aminophylline tablets.

But it was not until the 1970s that bronchodilator drugs were used for severe crises and corticosteroids to keep inflammation under control.

In the end, despite the fact that asthma has been known for over 2500 years, the causes have not yet been fully understood and a definitive cure has not been found. However, the drugs available today allow the disease to be effectively controlled.

Asthma: epidemiology

According to the World Health Organization (WHO), there are between 100 and 150 million people worldwide who suffer from this disorder.

The allergic form affects 50% of adults and 80% of children. Unfortunately, deaths related to this disease are about 180,000 each year, according to WHO data.

In America, it is estimated that around 3 million people fall ill with asthma every year, with prevalence rates constantly increasing, especially among children. In fact, estimates speak of about 10% of children affected by this pathology.

Despite being one of the most common chronic diseases in childhood, asthma can also affect adults, even in old age. In particular, among young people it is more frequent in boys in puberty and in girls after puberty.

However, in some cases, children’s asthma resolves as they grow older, although it may reappear a few years later.

Asthma: growing data in the world

However, worldwide there is an increase in cases of asthma, which, according to the WHO, depends above all on the phenomenon of urbanisation, ie the fact that more and more people live in cities.

In fact, living in urban areas means spending more time in closed spaces with little air circulation, more exposed to:

  • Dust.
  • Acari.
  • Smog.

In addition, according to some experts, this increase in cases is also due to the increase in the level of hygiene in developed countries. Thus, this phenomenon would have affected our immune system, causing it to have a major allergic reaction.

Finally, other factors may also be linked to the increased incidence of asthma, such as obesity and lack of exercise.

Asma: cause

There are two mechanisms by which asthma manifests itself.

inflammatory response

We all react to the presence of substances irritating the respiratory system by activating the mechanisms of inflammation in different ways:

  • Increase in the number of inflammatory cells that have the role of eliminating microorganisms.
  • Hypersecretion of mucus, or increased secretion of mucus that traps impurities in the air in order to eliminate them.
  • Bronchospasm, i.e. contraction of the muscle fibers of the bronchi and bronchioles: this process hinders the penetration of microorganisms into the alveoli.

Thus, in asthmatics, these responses are exaggerated, to the point of preventing air from passing through the lung, both in and out.

Furthermore, if not treated adequately, asthma can over time cause thickening of the walls of the bronchi and bronchioles and consequently chronically reduce airflow. In detail, this process is called airway remodeling.


Hyperactivity is the exaggerated reaction to the presence of irritants or allergens that induces bronchospasm. In fact, if in all people exposure to irritants causes the narrowing of the airways, in those with asthma this reaction is excessive.

Asthma: risk factors

Asthma is caused by various genetic and environmental factors and the specific role has not been well understood for all. In particular, some of these, such as genetic predisposition and exposure to sensitizing substances present in the environment, cause the appearance of the disease. Instead others, such as viruses, allergens, physical activity, etc. contribute to worsening symptoms.

So, here are the risk factors that most expose you to the disease.

Genetic predisposition

If you have a close relative who has asthma, you are more likely to develop the disease. For example, children of asthmatics have a higher risk, even if not the certainty of getting asthma.

The genetic predisposition to develop some allergic diseases, such as bronchial asthma, is also called atopy.

In fact, it is a phenomenon characterized by the excessive production of immunoglobulins E, also called IgE. Then, this IgE targets the most common allergens found in the environment, such as:

  • Pollen.
  • Mushroom spores.
  • Dust mites.
  • Animal hair.
  • Molds.
  • Some animal proteins.

Therefore, when our body comes into contact with these allergens, the already sensitized antibodies activate the inflammatory response. For this reason, atopy is the major risk factor for the onset of bronchial asthma and other allergic forms.


Asthma exacerbations are often caused by substances to which you are allergic. In this case, we speak of allergic bronchial asthma and asthmatics are atopic subjects.

However, it should be clarified that not all asthmatics are also allergic and not all allergy sufferers are asthmatics.

In detail, the most common allergens that can trigger asthma are:

  • Pollens: from grasses (wheat and corn), urticaceae (parietaria officinale), composite (ambrosia).
  • Dust mites.
  • Animal allergens, including domestic ones.

But exposure to allergens such as pollen can cause asthma to worsen only during a certain period, ie during the season in which these pollens are diffused in the air. This is why in this case we speak of seasonal and / or episodic asthma.

Respiratory infections

Both viral and bacterial infections, such as colds and flu, can often make asthma worse, triggering the onset or exacerbation of symptoms. Also for this reason the flu vaccination is indicated for all adult asthmatics.


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