Your asthma may be mild, moderate or severe. Treatment plans differ by symptom severity.
Asthma always causes lung inflammation and airway constriction, but its severity can vary dramatically. If you're mildly sensitive to allergy triggers such as pollen, mold or pet dander, or to irritants such as cigarette smoke, perfume or air pollution, your airways may become only slightly inflamed and tight, resulting in occasional bouts of wheezing, coughing or breathlessness. If you're extremely sensitive, however, the resulting inflammation and muscle tightening may permanently narrow your air passages, which can cause continuous wheezing and frequent asthma attacks.
To help determine the best way to treat your asthma, your doctor may rate it according to severity. The asthma rating system doctors generally use includes four levels: mild intermittent, mild persistent, moderate persistent and severe persistent. The higher the severity level of your asthma, the more aggressively your doctor will treat it.
Although the diagnosis and grading of asthma require medical expertise, you may get a general idea of your asthma's severity and optimal treatment from guidelines established by the National Asthma Education and Prevention Program.
How severe is your asthma?
To make an accurate assessment of your asthma's severity, you may need to keep a daily record of your asthma signs and symptoms for awhile. Whether you're tracking your own or your child's asthma episodes, take note of these signs and symptoms:
- Increased shortness of breath or wheezing (a whistling sound produced during exhalation)
- Disturbed sleep caused by shortness of breath, coughing or wheezing
- Chest tightness or pain
- Increased need to use a quick-relief inhaler containing a short-acting bronchodilator — a medication that opens airways by relaxing the surrounding muscles
- Intolerance of usual exercise
Lung function tests: Important indicators of severity
Your signs and symptoms may provide clues about your asthma severity, but they aren't conclusive proof that your asthma is mild, moderate or severe. Your doctor can make that determination only after conducting lung function (pulmonary) tests. The following tests are especially useful in grading asthma severity:
- Spirometry (forced expiratory volume, or FEV-1). You breathe into a mouthpiece connected to a device called a spirometer, which records the amount of air (forced expiratory volume) that you can exhale in one second. This measurement is called FEV-1. Your doctor compares your result with the predicted result for people of your age, sex, race and height who don't have asthma. This comparison is expressed as a percentage, with lower percentages indicating that you have less lung power than might be expected. For example, if your FEV-1 is lower than 60 percent, you may have severe persistent asthma.
- Peak expiratory flow (PEF). You blow into a small, hand-held device called a peak flow meter, which measures the rate at which you can force air out of your lungs. PEF is usually lowest when you get up in the morning and highest between noon and 2 p.m., so it's measured twice in each assessment: once in the morning before you use any asthma medication and again in the afternoon after you inhale a short-acting bronchodilator. As with FEV-1, your doctor compares your results with the predicted results for people of your age, sex, race and height who don't have asthma. PEF is expressed as a percentage, with lower percentages indicating that you have less lung power than might be expected. For example, if your PEF is lower than 60 percent, you may have severe persistent asthma. Your doctor also compares your morning and afternoon results with each other, and expresses the difference (PEF variability) as a percentage. In this case, higher percentages indicate that you have less lung power than might be expected. For example, if your PEF variability is greater than 30 percent, you may have moderate or severe asthma.
Here's how lung function measurements correspond to different grades of asthma severity:
| Level of severity | Forced expiratory volume (FEV-1) or Peak expiratory flow (PEF) | Peak expiratory flow (PEF) variability |
| Mild intermittent | At least 80% | Less than 20% |
| Mild persistent | At least 80% | 20% - 30% |
| Moderate persistent | 60% - 80% | Greater than 30% |
| Severe persistent | 60% or less | Greater than 30% |
Readings from your home peak flow meter won't tell you much about the severity of your asthma because the calibration varies from model to model. After your doctor makes a diagnosis of asthma, however, he or she can show you how to interpret the readings of a home peak flow meter so that you can accurately monitor your condition. You can also use a peak flow meter to help detect subtle increases in airway obstruction before you notice symptoms. If the readings are lower than usual, it's a sign your asthma may be about to flare up. Your doctor can give you instructions on how to deal with low readings.
Treating by severity for better control
Effective asthma control is defined as:
- Few or no chronic symptoms, day or night
- Few or no attacks
- No limitation of physical activity
- No missed days at work or school
- Minimal use of quick-relief inhalers
- Few or no adverse effects from medications
Treatment based on asthma severity can help you control your asthma. According to guidelines from the American Academy of Allergy, Asthma & Immunology and the American College of Allergy, Asthma & Immunology, asthma therapy should be flexible and based on changes in symptoms, which should be assessed thoroughly each time you see your doctor. Then, treatment can be adjusted accordingly.
"Each person with asthma reacts differently to medication, the environment, triggers, and changing allergens that affect symptoms," says James T. Li, M.D., an asthma and allergy specialist at the Mayo Clinic in Rochester, Minn., and lead author of the guidelines. "Assessing these factors requires strong communication between you and your doctor on an ongoing basis to determine whether changes in treatment should be made."
For example, if your asthma is well controlled, you may be able to take less medicine. On the other hand, if your asthma is uncontrolled or worsening, an increase in medication and more frequent visits with your doctor may be required.
For quick relief of asthma flare-ups (exacerbations), the treatment is usually the same across the board: an inhaled, short-acting bronchodilator such as albuterol (Proventil, Ventolin) or pirbuterol (Maxair). These medications, which belong to a class known as beta-2 agonists, open constricted airways.
If you have persistent asthma, whether it's mild, moderate or severe, you are likely to need long-term control medications. Used properly, these medications can reduce or eliminate your need to use a quick-relief inhaler. Long-term medications include:
- Inhaled corticosteroids, such as fluticasone (Flovent), budesonide (Pulmicort) and triamcinolone (Azmacort). They treat the underlying cause of asthma — inflammation — which is a precondition for the airway constriction that leads to asthma signs and symptoms.
- Inhaled, long-acting beta-2 agonists, such as salmeterol (Serevent) or formoterol (Foradil). Unlike the short-acting beta-2 agonists often used for quick relief, these bronchodilators have sustained effects that prevent airway constriction.
For moderate to severe persistent asthma, the preferred treatment is a combination of an inhaled corticosteroid and an inhaled long-acting beta-2 agonist. This approach often requires using two inhalers, but a combination inhaler — Advair, which contains both fluticasone and salmeterol — is available. In some cases, severe asthma may require additional treatment with an oral corticosteroid such as prednisone, methylprednisolone or hydrocortisone.
Alternative but less effective long-term control medications include:
- Leukotriene modifiers. These drugs are taken in pill form, either alone or in conjunction with an inhaled corticosteroid. Examples include montelukast (Singulair) and zafirlukast (Accolate).
- Theophylline (Uniphyl). This drug is taken in pill form, either alone or in conjunction with an inhaled corticosteroid. Although guidelines include it as an alternative to a long-acting beta-2 agonist in mild persistent and moderate persistent asthma, theophylline is rarely used in children.
- Cromolyn (Intal) and nedocromil (Tilade). These medications, taken by inhalation, are sometimes used instead of inhaled corticosteroids to treat mild persistent asthma.
You'll likely use a metered-dose inhaler — a hand-held device with a mouthpiece — to take inhaled medications. For people who can't use metered-dose inhalers (including anyone under age 5), doctors may recommend using a nebulizer, a device that converts medication into a mist and delivers it through a mask worn over your nose and mouth.
Last Updated: 01/18/2006