Persistent Asthma Classifications

woman coughing

People who suffer from severe persistent asthma usually experience asthma symptoms throughout the day on most days and have frequent symptoms at night as well. These symptoms tend to limit one's physical activity.

Asthma Classification

The classification of asthma is based on the severity of the condition. Classification is determined by:

  • The type of symptoms (difficulty breathing, wheezing, chest tightness, and coughing) a patient is exhibiting before treatment
  • The amount and speed of air the patient can blow (determined by conducting a lung function test or pulmonary function test)
  • It is important to note that a person in any asthma category can have severe asthma attacks, not just those suffering from severe persistent asthma.

Classification may change over time and asthma in children younger than 4 years old is difficult to diagnose and classify, as symptoms may be different from asthma in older patients.

Asthma has been classified into the following 4 categories, by the National Asthma Education and Prevention Program:

Intermittent Asthma

Asthma is considered intermittent if without treatment any of the following are true:

  • Symptoms occur two days or less per week and do not interfere with normal activities.
  • Nighttime symptoms occur two days or less per month.
  • When not having an asthma attack, lung function tests are normal (at 80 percent or more of the expected value) and vary little from morning to afternoon.

Mild Persistent Asthma

Asthma is considered mild persistent if without treatment any of the following are true:

  • Symptoms occur more than two days a week, but not every day, and nighttime symptoms occur three to four times a month.
  • Asthma attacks interfere with normal daily activities.
  • Lung function tests are normal when not having an attack (tests are 80 percent or more of the expected value) and may vary a small amount from morning to afternoon.

Moderate Persistent Asthma

Asthma is considered moderate persistent if without treatment any of the following are true:

  • A daily occurrence of symptoms and a short-acting inhaler is used every day.
  • Symptoms interfere with daily activities.
  • Nighttime symptoms occur more than one time a week, but do not happen every day.
  • Lung function tests are abnormal and varies more than 30 percent from morning to afternoon.

Severe Persistent Asthma

Asthma is considered severe persistent if without treatment any of the following are true:

  • Symptoms occur throughout each day and severely limit daily physical activities.
  • Nighttime symptoms occur often, sometimes every night.
  • Lung function tests are abnormal and may vary greatly from morning to afternoon.

Classification Spotlight: Severe Persistent Asthma

Working with a medical team that you trust and feel comfortable with is an important step in properly diagnosing and treating the severity of your asthma. Your asthma doctor should be monitoring the following factors in order to address your severe persistent asthma:

  • Frequency of symptoms (throughout the day)
  • Frequency of nighttime awakenings with asthma symptoms (often daily)
  • Use of a quick-relief inhaler (several times per day)
  • How much asthma interferes with daily activities (extremely limited)
  • Peak flow readings (less than 60 percent of personal best)
  • Whether asthma flares require use of oral steroids (two or more times a year)
  • Nighttime symptoms occur often, sometimes every night
  • Lung function tests are abnormal (a spirometry test of 60 percent or less of expected value), and peak expiratory flow (PEF) varies more than 30 percent from morning to afternoon

Treating Severe Persistent Asthma

Patients with severe persistent asthma are generally treated with a combination of asthma medications including:

  • Long-term control medicines (inhaled corticosteroids) that reduce inflammation of the airways to prevent asthma symptoms and asthma attacks
  • Long-acting bronchodilators and a quick-relief medicine (short-acting beta agonist or bronchodilator). This additional medication is used (as needed) to relieve acute symptoms by relaxing tightened muscles around the airways.
  • Severe persistent asthma may additionally be treated with anti-inflammatory medicines known as “leukotriene modifiers." These are taken in pill form and are used in combination with the other medications.

People with asthma may find that their severity of asthma fluctuates over the years. As severity fluctuates, so does medication and treatment, with the ultimate goal being to keep asthma under control. The goal of treatment for severe persistent asthma should be to control and reduce symptoms to that of intermittent asthma.

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Article Sources

  • Anti-Inflammatories: Leukotriene Modifiers. U.S. News & World Report. 
  • Fact Sheet: Treating Asthma. The American Academy of Allergy Asthma & Immunology Task Force. The Allergy Report.
  • How Is Asthma Diagnosed? National Heart Lung and Blood Institute, U.S. Department of Health and Human Services, National Institutes of Health.
  • Needs Assessment Report 2007. National Heart, Lung, and Blood Advisory Council Asthma Expert Working Group.