What does a peak flow meter reading in the yellow zone indicate?

A peak flow meter reading in the yellow zone indicates inadequate control of asthma. The yellow zone typically signifies that a person's asthma is not well-controlled and may require intervention. This range suggests that the patient's airflow is reduced, signaling that they may be experiencing asthma symptoms or that their asthma medications may need to be adjusted. This is a crucial indicator for patients to recognize that they may need to take their rescue inhaler, increase preventative treatments, or consult their healthcare provider for further evaluation and management.

In contrast, readings in the green zone would demonstrate effective asthma management and normal lung function, while readings in the red zone would indicate a severe asthma attack requiring immediate medical attention. Hence, the yellow zone serves as a warning that asthma control has declined and prompts necessary actions to prevent worsening of the condition.