How Do You Get Asthma?

How Does Asthma Develop?

Asthma can develop at any age, but it’s not always clear how you get it. The condition is sometimes hereditary, but it can also be caused by environmental triggers. If something irritates the lungs enough, the lining of the airway becomes inflamed and swollen, making it more difficult to breathe. Some of the most common causes of asthma include:

How Do You Get Asthma?


Children of parents with asthma are much more likely to have asthma. Although they may not be born with the condition, they tend to be more sensitive to environmental triggers that can cause asthma to develop. Twin studies show that if one identical twin has asthma, the other twin has a greater likelihood of also developing asthma.


Allergies are very closely linked with asthma. The most common allergens that trigger asthma are those that are inhaled, including:

  • Dust mites
  • Mold
  • Pollen
  • Animal dander

When someone has allergies, their immune system treats allergens like they’re harmful, which disrupts the body’s functions. This can lead to inflamed and swollen airways, the main characteristic of asthma.

Food allergies can also sometimes cause asthma attacks. This is less common than inhaled allergens, but the reaction is usually more severe.


Exercise is one of the most common causes of asthma, and most people with asthma experience symptoms while exercising. When you breathe normally, the air travels through the nasal passages. This moistens and warms the air. Because you tend to breathe through your mouth when you exercise, the air is colder and drier. This can cause the airways to contract, which results in coughing, wheezing, shortness of breath, and fatigue.


Smokers develop asthma at a higher rate than nonsmokers. When you inhale tobacco smoke, some of the substances can stay in the lining of the airways. The smoke also damages the cilia, which are tiny structures that remove dust and mucus from the airways. When dust, mucus, and other irritating substances accumulate in the airways, it can cause asthma attacks. Secondhand smoke can also cause a person to develop asthma.

Upper Respiratory Infections

Upper respiratory infections can cause narrowing and inflammation in the airways. Depending on the severity of the infection, this can cause the person to develop asthma or suffer from an asthma attack. Common symptoms of an infection that can lead to asthma include:

  • Shortness of breath
  • Wheezing
  • Coughing up mucus
  • Sore throat
  • Fatigue
  • Air Pollution

Air pollution can cause asthma to develop and can worsen already-existing asthma symptoms. Airborne particles in haze, airborne dust, and smoke can enter your lungs and damage the airways. This is especially common in cities with smog. Ozone, which is found in higher concentrations in cities with many cars, is also a major trigger of asthma attacks.


Researchers have only recently noticed a link between obesity and asthma, but several studies have confirmed that obese children are twice as likely to suffer from asthma as children at a healthy weight. Obese adults are five times as likely to be hospitalized from an asthma attack. Obesity can cause the narrowing of the airways in the lungs, which makes it more difficult to breathe and can trigger asthma attacks.