Asthma is a common chronic respiratory disease primarily affecting airway function, leading to recurrent episodes of breathlessness, wheezing, and coughing. It affects approximately 330 million people worldwide, significantly impacting patients' quality of life and health. The pathogenesis of asthma involves airway inflammation, hyperreactivity, and smooth muscle contraction, which cause airway narrowing and obstruct airflow.
The key to understanding asthma lies in its complex pathophysiology and multifaceted treatment strategies. Modern medicine has developed various approaches to control the condition, including pharmacotherapy, environmental control, and patient self-management. Early diagnosis and regular treatment can effectively reduce the frequency of acute attacks and improve lung function. This article provides a comprehensive overview of asthma, from causes and symptoms to diagnosis and preventive measures.
The etiology of asthma involves interactions between genetic and environmental factors, with genetics accounting for about 50% of cases. Children with a family history of allergic diseases have a 3 to 6 times higher risk of developing asthma. Environmental triggers include air pollutants, allergens (such as dust mites and pollen), cold air, and viral infections, which can induce airway hyperresponsiveness.
Genetic studies have identified specific chromosomal regions (such as 17q21) associated with asthma susceptibility. Patients often have comorbid allergic rhinitis or atopic dermatitis, forming the "Atopy March." Abnormal immune activity leads to excessive IgE antibody production, resulting in chronic airway inflammation.
Environmental exposures can directly stimulate airway hyperreactivity. Indoor allergens like dust mites, cockroach debris, and mold spores accumulate in enclosed spaces and may trigger acute attacks. Chemicals such as polycyclic aromatic hydrocarbons in secondhand smoke damage airway epithelial cells and promote chronic inflammation.
Climate factors like cold, dry air can induce bronchoconstriction. Wheezing immediately after exercise is called "Exercise-Induced Bronchoconstriction" (EIB). Workers exposed to chemical fumes or metal powders have a 2-3 times higher risk of developing adult-onset asthma.
Asthma symptoms vary among individuals, ranging from mild intermittent to severe, affecting daily activities. Typical symptoms include:
During an acute attack, patients may experience "airflow obstruction," leading to carbon dioxide retention. Severe attacks may result in "Silent Chest," where wheezing disappears, indicating severe airway obstruction and requiring emergency medical attention.
A small number of patients may present primarily with chronic cough, especially worsening at night or after cold exposure. This "Cough-Variant Asthma" is often misdiagnosed as upper respiratory infection. Children may show decreased activity tolerance, and adults may experience chest pain or respiratory muscle fatigue.
Asthma diagnosis requires a combination of clinical assessment, functional testing, and exclusion of other diseases. Physicians typically perform a three-step evaluation: history analysis, pulmonary function tests, and provocation tests.
Detailed symptom inquiry is crucial, including:
Pulmonary function testing (Spirometry) is the core diagnostic tool, measuring Forced Expiratory Volume in 1 second (FEV1) and Forced Vital Capacity (FVC) ratios. A reduced ratio that improves by more than 12% and an absolute increase of 200ml after inhalation of a short-acting bronchodilator confirms reversible airway obstruction.
Challenge tests such as methacholine or exercise challenge are used in atypical or difficult cases. Imaging studies (e.g., chest X-ray) mainly serve to exclude pneumonia, bronchitis, and other differential diagnoses.
Asthma treatment follows the "stepwise approach," adjusting medication intensity based on symptom severity. The goal is to control symptoms, prevent acute attacks, and maintain normal activity levels.
Long-term control medications include:
Short-acting beta-2 agonists (SABA), such as Salbutamol, are the first choice for acute attacks. Severe attacks may require oral corticosteroids (e.g., Prednisone) or biologic agents (e.g., anti-IgE monoclonal antibodies) to suppress excessive immune responses.
Prevention strategies involve environmental control and pharmacological prophylaxis. Environmental measures include:
Influenza and pneumococcal vaccines can reduce virus-triggered exacerbations. Studies show that influenza vaccination reduces hospitalization rates due to respiratory infections by 50%.
Patients with exercise-induced asthma can use "pre-treatment" strategies, such as inhaling SABA 15 minutes before exercise or warming up thoroughly. Those sensitive to cold should wear masks to keep warm in low temperatures.
Seek immediate medical attention if any of the following occur:
In chronic symptom management, if attacks occur more than twice a month, nighttime symptoms affect sleep, or daily activities are limited more than two days per week, reevaluate the treatment plan. Patients are advised to use an Asthma Action Plan for self-monitoring, and to be alert when peak flow readings fall below 80% of their personal best.
Children with symptoms such as growth retardation, persistent cough interfering with sleep, or significantly reduced exercise capacity should undergo specialist evaluation promptly. Adults with unexplained weight loss or persistent chest pain should be evaluated for comorbidities such as asthma and gastroesophageal reflux disease.
Breathlessness during exercise may be a manifestation of exercise-induced asthma, but it should be distinguished from other cardiopulmonary issues. It is recommended to use a bronchodilator before exercise and monitor symptom changes. If symptoms persist, a physician should evaluate whether treatment adjustments are necessary.
Does long-term use of inhaled corticosteroids impair the immune system?The dose of inhaled corticosteroids is designed for local action, with low absorption rates. When used according to medical advice, long-term use generally does not significantly affect the immune system. However, oral candidiasis can occur, and rinsing the mouth after use is recommended to reduce side effects.
How should asthma patients protect themselves during high AQI (Air Quality Index) days?When air pollution levels are high, outdoor activities should be avoided, and N95 masks should be worn if necessary. Home air filtration systems and regular cleaning of appliance filters can reduce the risk of acute attacks caused by fine particulate matter.
How should medication be adjusted during a cold?Colds can trigger worsening asthma symptoms. It is advisable to increase control medication frequency or follow medical instructions for rescue medication. If symptoms such as chest tightness or nighttime cough worsen, prompt medical evaluation is necessary, and short-term oral corticosteroids may be required.
Why is the statement "Asthma can be cured" considered a misconception?Asthma is a chronic airway inflammatory disease with no current cure. However, with regular medication and environmental control, symptoms can be fully managed and remission achieved. Patients should regularly communicate with their healthcare providers and adjust treatment plans accordingly to prevent long-term complications.
%201.svg)
Copyright © 2025 MedFrontiers. All Rights Reserved.
