NOTICE: Last date for pre Christmas delivery - 22/12/25 - must choose Next Day Delivery. Medisave is closed 25/12/25, 26/12/25 and 01/01/26. We cannot guarantee delivery times for orders placed between 24/12/25 and 02/01/26

The simple, accurate way to monitor asthma
100% is the asthmatic's best. The yellow zone will typically be set to start at 80% of the asthmatic's best while the red zone will typically start at 60%. Variability of PEFR of greater than 20% should alert the asthmatic to a possible asthma attack.