Researchers have uncovered a lot about what occurs during an asthma attack. Unfortunately, the exact reason why one person gets asthma while another does not remains unknown. One thing is certain: genetics play a big role. Like allergies, asthma tends to run in families. According to the Asthma and Allergy Foundation of America, if only one parent has asthma, the chances are nearly 1 in 3 that their child will have asthma. If both parents have asthma, the chances of their child having asthma increase to 7 in 10. However, the genes involved in developing asthma remain mostly unknown.
While genetics are a factor, it is clear that they are not the whole story. The genes involved likely confer a susceptibility to developing asthma instead of causing the disease directly. Many people who have asthma also have allergies and it is thought that certain genes may cause susceptibility to both diseases. Even so, just having the genes is not enough. In addition, you also need to come into contact with the right allergens or irritants that trigger a reaction in your lungs. Also, several environmental factors are known to increase the likelihood of developing asthma, including poor air quality, exposure to irritants, childhood exposure to secondhand smoke, and others.
Childhood Asthma
In the United States, nearly half of the people who have been diagnosed with asthma are children. Asthma is the leading cause of chronic illness in children. Although asthma can develop at any age, it most often starts in childhood. Recently, the prevalence of asthma in American adults and children has been increasing for unknown reasons. Interestingly, asthma is more common in boys than in girls, but after about age 20 it becomes more common in women than men.
Several studies have demonstrated that the time of gestation (i.e. during pregnancy) and the first few years of a child’s life are critical to determining whether or not a person will develop asthma in childhood. Premature birth or low birth weight both make an infant more susceptible to respiratory problems and increase the likelihood of developing asthma. Frequent respiratory infections in the early years can also make asthma more likely. Exposure to secondhand smoke also appears to increase asthma risk.
Adult-onset asthma
When asthma is diagnosed for the first time in someone older than 20, it is known as adult-onset asthma. Women are more likely than men to develop asthma as adults. A person can develop asthma at any time during life. Exposure to irritants on a long-term basis, such as secondhand smoke in the home, is a major risk factor for developing asthma later in life. Other factors include exposure to things like household chemicals and air pollution.
Main risk factors for asthma
To summarize, the main risk factors for developing asthma include:
- family history of asthma or allergies
- having allergies yourself
- low birth weight
- frequent respiratory infections in childhood or certain other illnesses in adulthood
- African American or Hispanic/Latino ethnicity
- growing up in a low-income environment
- living in a large urban area
- women who are pregnant or are experiencing menopause
- obesity
- gastroesophageal reflux disease (GERD)
- exposure to tobacco smoke before birth, in childhood, or as an adult
- exposure to environmental irritants, mold, dust, feather beds, or perfume
- exposure to occupational triggers, such as chemicals used in manufacturing
Exercise-induced asthma / bronchospasm
Some people only experience their asthma symptoms during or after exercise. However, exercise-induced asthma / bronchospasm should be anticipated in all asthmatics as exercise might trigger asthma symptoms in all sensitive people. If you suspect that you have exercise-related asthma you should discuss this and your symptoms with your doctor.