Family Health Guide

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Asthma: Diagnosis

Studies show that as many as 50 to 80 percent of kids who develop asthma have symptoms before their third birthday. Most children, however, are diagnosed with asthma at age 5 or older because these symptoms can be confusing to parents and even doctors. Fussy babies with frequent colds are not uncommon, and many toddlers continue to be active and happy despite wheezing and chest tightness (and keep in mind they don’t realize this isn’t a normal way to feel). Younger children also cannot describe how they are feeling and cannot perform the lung function tests needed for diagnosis. There are, of course exceptions; some doctors will diagnose even infants with severe symptoms, although they might call is reactive airway disease (RAD). See our Age-by-age Guide if you think your infant or toddler falls into this category.

However, if you have a child of any age with frequent wheezing (four or more episodes in one year that lasted longer than a day and disrupted sleep), you will want to call your pediatrician and set up an appointment (and if they are struggling to breathe, don’t wait -- call 911). You may also want to consult your ped if your child has one or more of the major asthma indicators or at least two of the minor listed below.


  • A parent with asthma
  • A sibling with asthma
  • Eczema
  • Has tested positive for airborne allergens


  • Allergic rhinitis
  • Wheezing in the absence of a cold or virus
  • Food allergies, especially to eggs, milk or peanuts