You should measure your peak flow in the morning and evening before taking your inhalers or as advised by your doctor or nurse.
Peak flow changes throughout the day and is often slightly lower in the morning than the evening.
A chart called a ‘nomogram’ can be used to estimate your predicted peak flow based on if you are male or female, your age and height.
It is important to remember that everyone is different and you should be guided by what is normal for you.
Measuring your peak flow when you feel well will establish your normal or best peak flow.
