Asthma: What Is, Causes, Symptoms, and Risk Factors

this narrowing is reversible, either spontaneously or with bronchodilators.

Asthma symptoms can vary widely among individuals. Some people may only experience symptoms during specific periods, such as the pollen season for certain allergies or exposure to cold air or physical exertion. Others may have frequent daily exacerbations. While asthma is a chronic condition that cannot be cured, it can be effectively managed, allowing most individuals to lead a life without significant restrictions.

Asthma can be a serious condition, so even infrequent attacks should be treated to prevent chronic inflammation from causing lasting changes to the respiratory tract.

Causes

Asthma is caused by an inflammatory process in the bronchi. Even in a symptom-free period, the bronchial mucosa contains numerous inflammatory cells, including eosinophils and lymphocytes, and the thickness of the bronchial wall increases due to the hypertrophy of smooth muscles and mucus-secreting cells.

Mechanism

During an asthma attack, the bronchi become significantly narrowed. There are several causes of this phenomenon:

• Spasm of the smooth muscles of the bronchi (the muscles in the bronchial wall tighten, causing a reduction in the lumen of the bronchi)
• Edema of the bronchial mucosa (the bronchial wall is swollen due to the infiltration of inflammatory cells and increased leakage of fluid from the blood vessels)
• An increased amount of mucous material accumulates in the lumen of the bronchi

Short-term asthma attacks primarily result from bronchial muscle spasms, while the underlying cause of disease exacerbation is mainly the intensification of inflammation in the bronchial mucosa. This inflammation leads to an increase in the number of eosinophils and lymphocytes. Inflammatory cytokines secreted by these cells contribute to bronchial muscle spasms, increase vascular permeability (allowing fluid to leak from blood vessels), enhance mucus secretion, and cause further influx of inflammatory cells.

Bronchial narrowing significantly raises resistance to airflow, resulting in a feeling of shortness of breath. The respiratory muscles must work harder to overcome this increased resistance, which is why patients often experience shortness of breath during the initial phase of an attack. If the attack is severe, lung ventilation—the amount of air inhaled per minute—may be inadequate, further exacerbating the sensation of breathlessness.

Different Factors

Coughing can stem from various factors. One of the primary causes is the irritation of receptors in the mucous membrane, which is triggered by mediators released by inflammatory cells, swelling of the mucous membrane, and the accumulation of secretions in the bronchi. During an asthma attack, the secretion volume in the bronchi increases, making it difficult to expectorate and further obstructing airflow.

The intensity of shortness of breath can be temporarily alleviated by fast-acting bronchodilators. The most commonly used are fast-acting β2-agonists, which can be administered through inhalation (via an inhaler or nebulizer). These medications relax the smooth muscles of the bronchi, widening the air passages and facilitating airflow, easing breathlessness. However, for short-term episodes of breathlessness—such as those triggered by exercise, strong odors, or stress—this treatment alone may not be sufficient. Additionally, bronchodilators do not address other underlying causes of shortness of breath, including swelling of the bronchial walls and increased mucus production. Therefore, it is essential to also use a medication that targets the inflammatory process in the bronchi.

Risk Factors

Asthma is typically accompanied by attacks of shortness of breath and coughing at night and in the early morning. However, nocturnal symptoms do not occur in all patients. Shortness of breath often occurs after physical exertion (the attack usually develops after the exertion has ended).

Other factors causing shortness of breath attacks include:

• In patients with atopic asthma (allergic), contact with an allergen to which the patient is allergic (e.g., exposure to dust, pollen, or entering a room where a cat has been)
• Irritating factors (e.g., aerosols, paint fumes), which may be related to occupational exposure
• Stress or strong emotions
• Tobacco smoke (active smoking or passive exposure to tobacco smoke)
• Air pollution
• Some medications (e.g., acetylsalicylic acid or other non-steroidal anti-inflammatory drugs)

Long-lasting asthma exacerbations are often caused by viral infections of the upper respiratory tract.

Symptoms

Asthma is under control if symptoms occur sporadically (less than 3 times a week), asthma attacks do not wake the patient at night do not interfere with everyday life and there are no exacerbations of the disease.

Cough

A cough in asthmatics is usually dry (without expectoration of sputum). Only sometimes does a coughing attack end with the expectoration of a small amount of whitish, thick sputum. The cough is often accompanied by shortness of breath. Sometimes the patient coughs up into an asthma attack – at first there is a cough, which increases, and eventually shortness of breath and wheezing join in. Coughing attacks can wake the patient up at night. In some patients, cough is the only symptom of asthma. It is the so-called cough variant of asthma. Remember, however, that not every chronic cough is a symptom.

The Sensation of Tightness in the Chest

A feeling of tightness in the chest often accompanies shortness of breath. Many patients describe this sensation as a girdle that surrounds the chest, making it difficult to breathe freely. It’s important to note that chest pain is not a symptom. If you experience chest pain—especially if it is not directly related to asthma attacks (for example, burning behind the sternum, pain in the lower part of the chest, or pain that worsens with deep breaths)—you should consult a doctor.

Wheezing

Wheezing is a symptom often associated with shortness of breath. It occurs when the bronchi narrow, which is a key factor in an asthma attack, making exhalation more difficult than inhalation. During an attack, exhalation may be significantly prolonged as air squeezes through these narrowed passages, often resulting in whistling sounds. A doctor evaluates the presence and intensity of these sounds by listening to the lungs with a stethoscope. In some cases, the wheezing can be so loud that it is audible to the patient or those nearby.

Severity of Symptoms

Asthma attacks have varying degrees of intensity. Some are almost imperceptible, and the most severe ones can lead to a threat to life. You need to learn to recognize severe asthma attacks to react appropriately. Most of us know our disease well enough to know when an attack is severe when it does not subside as quickly as usual, and you will need a doctor’s help.

Symptoms requiring urgent call for medical help include:

• Inability to speak a sentence (due to shortness of breath, only single words can be spoken)
• Dizziness and increasing lightheadedness
• Fatigue and increasing drowsiness
• No improvement and further worsening shortness of breath despite a fast-acting bronchodilator

Treatment

The patient collaborates with the doctor in managing asthma treatment.

The more a patient understands asthma, the better they can work alongside the doctor to create a treatment plan and adjust it independently based on the principles established with the doctor.

You and your doctor should work together to create a written asthma action plan. This plan should include essential information:

• How to use medications
• How to monitor the severity of the disease
• When to see a doctor
• If and what modifications to treatment can be made independently
• How to deal with an asthma exacerbation

A written action plan is useful. It helps both those who have difficulty remembering how to use medications and those who know a lot about asthma and want to have a greater influence on the treatment they are using.

Identification and Reduction of Exposure to Risk Factors

The patient, together with their doctor, should try to identify the factors that cause asthma symptoms and develop methods to reduce exposure to these factors or limit their adverse effects. Symptoms are most often caused by:

• Allergens in the environment
• Physical exertion
• Allergens in the workplace
• Chemical substances
• Viral infections
• Strong odors
• Stress and strong emotions
• Tobacco smoke

Physical Exercise

It is worth remembering that physical exercise is an essential component of a healthy lifestyle and should not be avoided. Effective methods are available to prevent asthma attacks caused by exercise.

Assessment of Disease Control

The basis for a proper assessment of asthma control is the assessment of the frequency and severity of asthma symptoms by a doctor. However, the doctor will only know what the patient tells them.

Information obtained from the patient is of great value, because asthma symptoms and lung function change over time. Neither a one-time examination by a doctor nor spirometry can replace them. Therefore, the patient should be familiar with the symptoms of asthma and be able to assess the severity of the disease over time. A diary kept by the patient, in which he records symptoms, can be invaluable help. Additionally, patients with severe asthma may benefit from daily PEF monitoring.

Pharmacological Treatment

The most important thing for the patient is to understand the difference between control medications and medications used as needed.

Control drugs are used regularly, regardless of whether asthma symptoms are present or not. They usually do not work immediately, and the patient only feels the effect of their use after a few weeks. These drugs include:

• Inhaled glucocorticosteroids – the most important drugs used in asthma, they are safe and effective. They inhibit the inflammatory process in the bronchi, which is the basis of asthma, reduce the severity of symptoms, improve lung function, and reduce the frequency of exacerbations.
• Long-acting β2-agonists – they relax the bronchi, and their effect lasts for many hours, which is why they are usually used twice a day.
• Leukotriene antagonists – inhibit the harmful effects of leukotrienes, i.e., substances released from inflammatory cells that intensify bronchoconstriction and the inflammatory process.
• Oral glucocorticosteroids – one of the basic groups of drugs used in the treatment of exacerbations. In chronic treatment, they are used as a “last resort” only when all other drugs fail. Chronic use causes numerous, often dangerous side effects, which is why they are used as a last resort, only in patients with very severe asthma.
• Monoclonal antibodies against IgE inhibit the action of immunoglobulin E, effectively blocking allergic reactions. These antibodies are administered subcutaneously to patients with severe asthma of allergic origin, typically every 2 or 4 weeks.

Principles of Medication Use

Disease-controlling medications should be taken regularly according to your doctor’s recommendations, even if you are not experiencing symptoms. The absence of shortness of breath and coughing attacks is not an indication to stop taking asthma control medications without consulting a doctor. Only anti-inflammatory control medications affect the cause of the disease, other asthma medications only alleviate its symptoms.

Emergency medications are taken to relieve symptoms and exacerbations and as a preventive measure before physical exertion. They do not affect the course of the disease, and increased use should be reported to the doctor. Emergency medications should be carried with you at all times. After using some inhaled glucocorticosteroid preparations, it is advisable to rinse your mouth and throat with water.

Each patient should have a written asthma action plan and follow the recommendations contained therein. The doctor selects the intensity of treatment based on the severity of asthma symptoms and lung function. If the treatment is not sufficient to control asthma, the doctor increases its intensity.

Remember that this information is indicative and does not constitute a basis for independent (without the help of a doctor) modification.

Sources

• What Is Asthma?. NIH.
  https://www.nhlbi.nih.gov/health/asthma
• Causes and Triggers. NIH.
  https://www.nhlbi.nih.gov/health/asthma/causes
• Asthma. NIH.
  https://www.ncbi.nlm.nih.gov/books/NBK430901/
• Cough. NIH.
  https://www.ncbi.nlm.nih.gov/books/NBK493221/
• Dyspnea. NIH.
  https://www.ncbi.nlm.nih.gov/books/NBK499965/
• Wheezing. NIH.
  https://www.ncbi.nlm.nih.gov/books/NBK482454/
• Treatment and Action Plan. NIH.
  https://www.nhlbi.nih.gov/health/asthma/treatment-action-plan
• Asthma Medications. NIH.
  https://www.ncbi.nlm.nih.gov/books/NBK531455/