How do you get asthma
Pro Research Analysisby 
Searched over 200M research papers
Consensus Meter
Understanding How Asthma Develops
Asthma is a chronic inflammatory disease of the airways that affects millions of people worldwide. The development of asthma is influenced by a combination of genetic, environmental, and immunological factors. This article explores the key mechanisms and triggers that contribute to the onset of asthma.
Genetic and Environmental Factors in Asthma Development
Asthma has a strong genetic component, with genome-wide association studies identifying variations in several genes that slightly increase the risk of developing the disease. These genetic predispositions interact with environmental factors, such as exposure to allergens, pollutants, and respiratory infections, to trigger asthma symptoms. Notably, the prevalence of asthma is increasing in regions that have adopted aspects of the Western lifestyle, suggesting that environmental changes play a significant role in the disease's development.
Role of Respiratory Infections
Respiratory viral infections, particularly those caused by rhinovirus (RV) and respiratory syncytial virus (RSV), are significant triggers for asthma exacerbations. RV is the most prevalent pathogen and is associated with a higher risk of developing atopic asthma, while RSV is more likely linked to non-atopic asthma. These viruses can disrupt the airway epithelial barrier and create a Th2-biased inflammatory environment, which increases susceptibility to asthma.
Airway Epithelium and Immune Response
The airway epithelium plays a central role in asthma pathogenesis. It acts as a barrier to inhaled allergens and pathogens and is involved in the immune response. In asthma, the airway epithelium's structure and function are impaired by chronic allergic inflammation, making it more vulnerable to infections and allergen penetration. This impairment leads to the release of chemokines and cytokines that induce inflammation and contribute to asthma symptoms such as wheezing, chest tightness, and cough.
Cytokine Networks and Inflammatory Pathways
Asthma is characterized by chronic inflammation of the airways, driven by type 2 cytokines such as interleukin-4 (IL-4), IL-5, and IL-13. These cytokines promote airway eosinophilia, mucus overproduction, and bronchial hyperresponsiveness. However, not all asthma patients exhibit a type 2 response. Some have "type 2-low" asthma, which involves different immune features such as airway neutrophilia and systemic inflammation related to obesity. Understanding these diverse mechanisms is crucial for developing targeted therapies.
Structural Changes and Epigenetic Mechanisms
Asthma involves both inflammation and structural remodeling of the airways, which may begin in utero and continue throughout life. Epigenetic mechanisms, which involve changes in gene expression without altering the DNA sequence, play a role in how genetic and environmental factors interact to influence asthma development. These mechanisms can operate prenatally and during childhood, affecting the risk of developing asthma later in life.
Conclusion
Asthma is a complex disease with multiple contributing factors, including genetic predispositions, environmental exposures, respiratory infections, and immune responses. The interplay between these factors leads to the chronic inflammation and structural changes characteristic of asthma. Ongoing research into the specific pathways and mechanisms involved in asthma development holds promise for more personalized and effective prevention and treatment strategies.
Sources and full results
Most relevant research papers on this topic