Asthma diary

An asthma diary helps you keep track of how well you are managing your asthma. You record your peak expiratory flow (PEF), any symptoms and what triggers them, and any quick-relief medication you use to relieve the symptoms.

Measure your PEF often, every morning and evening if possible, and record it in your diary. If you have symptoms or an asthma attack, record the trigger (if possible), the symptoms, and what kind of medication you used for relief and how well it worked. Also note if you had to contact your health professional or seek emergency care. This can help you determine your triggers and help your health professional monitor your treatment.

It may be helpful to record your PEF using the same green, yellow, and red zone system used in your asthma action plan.

Here is an example of how to use an asthma diary.

Week of October 12

My personal best is 400 liters per second. My:

  • Green zone is 320 to 400 liters per second (80% to 100% of my personal best). To figure 80% of your personal best peak flow, multiply your best flow (in this example, 400) by 0.80 (in this example, you get 320).
  • Yellow zone is 200 to 319 liters per second (50% to less than 80% of my personal best). To figure 50% of your personal best peak flow, multiply your best flow (in this example, 400) by 0.50 (in this example, you get 200).
  • Red zone is less than 200 liters per second (less than 50% of my best).

My current long-term medications are fluticasone and salmeterol.

Example of asthma diary
Date AM/PM PEF Trigger Symptoms Quick-relief medication and response Red zone visit to doctor/hospital?





350 a.m.

300 p.m.


Beta2- agonists

Improved PEF



Swimming Wheezing

Beta2- agonists

Eliminated wheezing


Click here for a blank asthma diary template(What is a PDF document?) .

Last Updated: April 21, 2009

related physicians

related services

Bon Secours International| Sisters of Bon Secours USA| Bon Secours Health System

This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Privacy Policy. How this information was developed to help you make better health decisions.

© 1995-2010 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.