What does a peak flow meter measure in respiratory health?

A peak flow meter is an important tool used in respiratory health to measure the maximum speed at which a person can forcibly exhale air from their lungs, which is crucial for assessing lung function. This measurement, known as peak expiratory flow rate (PEFR), helps in monitoring conditions such as asthma and other obstructive airway diseases.

The ability to measure the maximum speed of expiration provides vital information about the airway's status and can indicate whether the airways are narrowing or if there are any obstructions. By regularly monitoring peak flow readings, patients and healthcare providers can better manage respiratory issues, tailor treatment plans, and identify early signs of asthma exacerbations or other breathing problems.

While the other options mention important aspects of respiratory health, they do not pertain specifically to the function of a peak flow meter. For instance, the amount of air inhaled would typically be measured by a spirometer, total lung capacity involves more comprehensive lung evaluation, and the effectiveness of medication would require different assessment techniques, such as monitoring symptoms or conducting lung function tests.