Tests and diagnosis

By Mayo Clinic Staff

Asthma can be hard to diagnose. Your child's doctor will consider the nature and frequency of symptoms and may use tests to rule out other conditions and to identify the most likely cause of his or her symptoms.

A number of childhood conditions can have symptoms similar to those caused by asthma. To make things more complicated, these conditions also commonly co-occur with asthma. So your child's doctor will have to determine whether your child's symptoms are caused by asthma, a condition other than asthma, or both asthma and another condition. Some conditions that can cause asthma-like symptoms include:

  • Rhinitis
  • Sinusitus
  • Acid reflux or gastroesophageal reflux disease (GERD)
  • Airway abnormalities
  • Vocal cord dysfunction
  • Respiratory tract infections such as bronchiolitis and respiratory syncytial virus (RSV)

The doctor will ask for a detailed description of your child's symptoms and health. Your child may also need medical tests.

  • In children 6 years of age and older, doctors diagnose asthma with the same tests used to identify the disease in adults. Lung function tests (spirometry) measure how quickly and how much air your child can exhale. Your child may have lung function tests at rest, after exercising and after taking asthma medication. Allergy skin testing also may be needed.
  • In younger children, diagnosis can be difficult because lung function tests aren't accurate before 6 years of age. Some children simply outgrow asthma-like symptoms over time. Your doctor will rely on detailed information you and your child provide about symptoms. Sometimes a diagnosis can't be made until later, after months or even years of observing symptoms.

If you suspect your child has asthma, it's important to see a doctor as soon as possible. Early diagnosis and proper treatment can prevent disruptions from daily activities such as sleep, play, sports and school. It may also prevent dangerous or life-threatening asthma attacks.

For children younger than age 3 who have symptoms of asthma, the doctor may use a wait-and-see approach. This is because the long-term effects of asthma medication on infants and young children aren't clear. If an infant or toddler has frequent or severe wheezing episodes, a medication may be prescribed to see if it improves symptoms.

Allergy skin tests for allergic asthma

If your child seems to have asthma that's triggered by allergies, the doctor may want to do allergy skin testing. During a skin test, the skin is pricked with extracts of common allergy-causing substances and observed for signs of an allergic reaction. This test may help identify whether your child is allergic to animal dander, mold, dust mites or other allergens. This information can be useful in taking steps to help your child avoid his or her particular asthma triggers.

Mar. 05, 2013