Finding Your Personal Best
Your personal best is the highest number you can achieve on a peak flow meter over a 2- to 3-week period when your asthma is under good control.
Good control is when you feel good and don't have any asthma symptoms. Everyone's asthma is different, and your best peak flow number may be higher or lower than someone else's of your height, weight, and gender.
Your personal best number is important, because it's the basis of your asthma action plan.
Starting out
To find your personal best (the highest number you can achieve on a peak flow meter), take peak flow readings at least twice a day for 2 to 3 weeks:
- When you wake up and between noon and 2:00 PM
- Before and after you take your short-acting inhaled medicine for quick relief, if you take this medicine
- As instructed by your doctor
- Write down the number you get for each peak flow reading. The highest peak flow number you had during the 2 to 3 weeks is your personal best
- This number can change over time, so ask your doctor when to check for a new personal best
Note: These times are only for finding your personal best peak flow. To check your asthma each day, take your peak flow in the morning.
Your peak flow zones
Your peak flow zones are based on your personal best peak flow number. The zones will help you check your asthma and take the right actions to keep it controlled.
- Measure your peak flow when you wake up, before taking your medicine. Write down your peak flow number in the diary every day
- Take your peak flow at any other time your doctor suggests
Green Zone (80%-100% of your best) means your asthma is in good control with no symptoms. This is where you should be every day. Take your medications as usual.
Yellow Zone (50%-79% of your best) demands that you take action to get this asthma episode under control. You may be experiencing mild to moderate symptoms: coughing, wheezing, shortness of breath, or chest tightness. You may need to step-up your medication temporarily. If your readings are in the yellow zone, even after taking your rescue medication that your asthma action plan specifies, contact your doctor.
Red Zone (less than 50% of your best) signals a medical emergency. You may be coughing, very short of breath, and/or the skin between your ribs or on your neck may be pulled in tight. You may have trouble walking or talking. Take your rescue medication and anti-inflammatory medications (based on your asthma action plan) and contact your doctor immediately.
For more on peak flow meters, see Using A Peak Flow Meter.
For a quick, easy-to-use way to keep track of your peak flow numbers, create your personalized Peak Flow Diary: click here.
