Disease Origin
Asthma does not have a single cause. Instead, it develops from a combination of different risk factors.
Asthma symptoms can sometimes resemble those of a common cold, but asthma is not contagious. You cannot catch asthma from another person.
Risk Factors
Some factors can increase the chance of developing asthma, especially when more than one is present. These factors can be genetic or non-genetic.
Genetic Factors
- several genes may contribute to asthma
- no single gene is solely responsible for asthma
Non-Genetic Factors
- Atopy (Allergic Sensitivity)
- Exposure to allergens l
- includes seasonal pollen, food allergens, household irritants (mold or dust), chemicals, paint fumes, hair spray, and many more
- Microbiome and Immune System Develoment
- Limited exposure to certain bacteria and allergens in childhood
- Prenatal and perinatal factors (before and shortly after birth)
- Premature birth (being born before 36 weeks of pregnancy)
- Exposure to tobacco smoke during pregnancy
- Young maternal age (younger than 20 years old)
- Vitamin D deficiency during pregnancy
- Lack of breastfeeding
- Viral respiratory tract infections
- Frequent viral respiratory infections during infancy and early childhood,
- especially RSV and human rhinovirus infections
- Air pollution exposure in early childhood
- Living in areas with high air pollution (e.g., near busy roads)
- Exposure to indoor pollutants (e.g., smoke from gas-fired appliances or indoor fires)
- Early puberty in girls
- Hormonal changes during early puberty