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Asthma is a lung disease that causes breathing problems. The breathing problems can be mild or severe. Sometimes the breathing problems can stop people from doing things they like to do and can make them feel sick. In some cases asthma can be life threatening. The causes of asthma are not the same for everyone. Some people develop asthma because of the way their bodies react to infection - mainly viral infection. Other people have asthma because they have allergies - which means their bodies react to substances (called allergens) that normally do not cause problems - like pollen, dust, or mold.

Asthma is a chronic disease which means you can't cure it but you can learn how to manage it so that you can have a healthy and active life. See tips for controlling asthma.

Asthma attacks

Asthma attacks feel different for different people. Some people describe an attack as coughing, not being able to get enough air, wheezing, or tightness in the chest. You might have one or more of these symptoms or different ones. Asthma triggers usually cause asthma attacks.

About asthma triggers

Asthma symptoms (like coughing or wheezing) are usually started or "triggered" by something that bothers your lungs. Some common triggers are:

  • Dust
  • Smoke
  • Mold or mildew
  • Colds or flu
  • Dogs, cats or other animals with fur
  • Cockroaches
  • Pet birds
  • Pollen from trees, grasses and weeds
  • Strong smells from household cleaners or perfumes
  • Weather changes or very cold air
  • Air pollution
  • Running, playing, or working hard
  • Crying, laughing or yelling
  • Aspirin or other medicine

These are just examples, and there may be other things that trigger asthma symptoms.

Who gets asthma

  • Asthma is common: Asthma is the most common chronic disease of childhood.
  • Asthma causes people to miss out on every day activities: Every year there are 100 million days of restricted activity due to asthma.
  • Missed school days: U.S. children miss 14 million days of school every year because of asthma (CDC).
  • Hospital visits: Asthma is one of the most common reasons for children younger than 15 years of age to need hospital care.
  • People can learn to take care of their asthma: People with asthma can be healthier when they learn how to reduce their triggers and use the right kind of asthma medicines.

Why asthma is more common than before

No one knows for sure why the number of children with asthma is increasing but asthma experts have suggested these reasons:

  • They spend more time indoors and are exposed to more indoor allergens like smoke from cigarettes, pets, mold and dust.
  • They are exposed to fewer viruses and bacteria than they were many years ago because of improved living conditions
  • They get less physical activity (less exercise)
  • They are overweight or obese
  • Green cleaning recipes for reducing indoor asthma