Which of the following conditions indicates a yellow zone reading (50-80%)?

A yellow zone reading in asthma management indicates that the patient is experiencing a degree of airway obstruction and is at risk for an exacerbation. Specifically, it is defined as a peak flow measurement between 50-80% of the patient's personal best. This range suggests that the asthma may not be well controlled, and the patient should take action, such as using a rescue inhaler or adjusting medications, and may need to monitor their symptoms more closely.

Understanding that increased asthma symptoms is associated with a yellow zone reading aligns with the clinical practice of using peak flow meters to guide treatment. The yellow zone serves as a warning signal to the patient that their asthma is worsening and requires attention to avoid progressing to a potential crisis.

In contrast, good control of asthma and clear peak flow readings would fall into the green zone, where the patient experiences minimal to no symptoms and maintains peak flow readings above 80% of their personal best. Similarly, minimal risk of exacerbation would also indicate that the patient's asthma is in control, correlating with peak flow readings that are consistently in the green zone rather than the yellow.