Asthma is a chronic lung disease that inflames and narrows the airways. Asthma causes recurring periods of wheezing , chest tightness, shortness of breath, and coughing. The coughing often occurs at night or early in the morning.

Asthma affects people of all ages, but it most often starts in childhood. In the U.S., more than 22 million people are known to have asthma. Nearly 6 million of these people are children.


The airways are tubes that carry air into and out of your lungs. People who have asthma have inflamed airways. This makes the airways swollen and very sensitive. They tend to react strongly to certain substances that are breathed in.

When the airways react, the muscles around them tighten. This causes the airways to narrow, and less air flows to your lungs. The swelling can also worsen making the airways even narrower. Cells in the airways may make more mucus than normal. Mucus is a sticky, thick liquid that can further narrow your airways.

This chain reaction can result in asthma symptoms. Symptoms can happen each time the airways are irritated.

Sometimes symptoms are mild and go away on their own or after minimal treatment with an asthma medicine. At other times, symptoms continue to get worse. When symptoms get more intense and/or additional symptoms appear, you call it an asthma attack. Asthma attacks are also called flareups or exacerbations.

It's important to treat symptoms when you first notice them. This will help prevent the symptoms from worsening and causing a severe asthma attack. Severe asthma attacks may require emergency care, and they can cause death.


Asthma can't be cured. Even when you feel fine, you still have the disease and it can flareup any time.


The exact causes of asthma isn't known. Certain family genes and environmental exposures can cause asthma to develop. These factors may include:
  • An inherited tendency to develop allergies, called atopy.
  • Parents who have asthma.
  • Certain respiratory infections during childhood.
  • Contact with some airborne allergens or exposure to some viral infections in infancy or early childhood when the immune system is developing.
If asthma or atopy runs in your family, exposure to airborne allergens ( examples: house dust mites, cockroaches, and possibly cat or dog dander) and irritants ( example: tobacco smoke) may make your airways more reactive to substances in the air you breathe.


Young children who have frequent episodes of wheezing with respiratory infections, as well as other certain risk factors, are at the highest risk of developing asthma that continues beyond 6 years of age. These risk factors include having allegies, eczema, or parents who have asthma.

Most, but not all, people who have asthma have allergies.

Some people develop asthma because of exposure to certain chemical irritants or industrial dusts in the workplace. This is called occupational asthma.


Your primary care doctor will dignose asthma based on your medical history, a physical exam, and results from tests. Your doctor will figure out what your level of asthma severity is - that is, whether it's intermittent, mild, moderate, or severe. You severity level will determine what treatment you will start on.

You may need to see an asthma specialist if:
  • You need special tests to be sure you have asthma.
  • You've had a life-threatening asthma attack.
  • You need more than one kind of medicine or higher doses of medicine to control your asthma.
  • You have overall difficulty getting your asthma well controlled.
  • You're thinking about allergy treatments.
  • Lung Function Test: Spirometry - this test measures how much air you can breathe in and out; check how your lungs are working.
  • Chest X-ray.
  • Bronchoprovocation - a test to measure how sensitive your airways are.
  • Quick relief medicines (example: quick relief inhaler for asthma)
  • Long term control (examples: cromolyn, nedocromil, theophylline)

Currently, there isn't a way to prevent asthma. However, you can take steps to control the disease and prevent its symptoms by doing the following:
  • Learn about your asthma and how to control it.
  • Follow your doctor's written asthma action plan.
  • Use medicines as your doctor directs.
  • Identify and avoid things that make your asthma worse as much as you can.
  • Keep track of your asthma symptoms and level of control.
  • Get regular check-ups for your asthma.