Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Asthma Health Center

Font Size

Asthma Action Plan: Yellow Zone - Topic Overview

An asthma action plan is based on zones defined by your symptoms or your peak flow, or both. It tells you what to do if you have a sudden increase in your asthma symptoms (asthma attack).

The yellow zone may mean that you are having an asthma attack or that your medicine needs to be increased.

When symptoms are present, they may be mild to moderate, or they may keep you from your usual activities or disturb your sleep. Symptoms can include:

  • Coughing and wheezing.
  • Feeling short of breath and having chest tightness. (Children may express chest tightness as a stomachache.)

In the yellow zone, your peak expiratory flow is 50% to 80% of your personal best peak flow measurement. To find 80% of your personal best, multiply your personal best measurement by 0.80. For example, if your personal best flow is 400, then 80% of that is 400 times 0.80, which is 320. And 50% of your personal best would be 400 times 0.50, which is 200. In this example, the yellow zone would be any value from 200 to 320. You may not have any symptoms, but your lung function is reduced.

Treatment for symptoms in the yellow zone includes the following:

  • Take your medicine according to your asthma action plan.
  • If symptoms do not improve within 20 to 60 minutes or if your peak expiratory flow remains less than 70% of your personal best measurement, or if both, then follow the red zone instructions of your asthma action plan, because your lungs are not responding to medicine.

If you keep going into the yellow zone from the green zone, talk with your doctor. Your regular medicine may need to be changed.

    WebMD Medical Reference from Healthwise

    Last Updated: /2, 14 1
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
    Next Article:

    Asthma Action Plan: Yellow Zone Topics

    When Is Your Asthma Worse?

    When Is Your Asthma Worse?

    Take the WebMD Asthma assessment to get Personalized Action Plan

    Start Now

    Today on WebMD

    Lung and bronchial tube graphic
    5 common triggers.
    group jogging in park
    Should you avoid fitness activities?
    asthma inhaler
    Learn about your options.
    man feeling faint
    What’s the difference?
    Madison Wisconsin Capitol
    woman wearing cpap mask
    red wine pouring into glass
    Woman holding inhaler
    Man outdoors coughing
    Lung and bronchial tube graphic
    10 Worst Asthma Cities