Purpose of Peak Flow Meters

Asthma refers to a chronic inflammatory disease that affects the airways and is characterized by such symptoms as coughing, shortness of breath and chest tightness. A peak flow meter measures an asthmatic person's lung function.

Function

• A peak flow meter device measures the peak expiratory flow rate, or the air flowing out of an individual's lungs, as that individual blows into the meter. Peak flow meters determine the degree of airway narrowing before an asthma attack.

Peak Flow Zones

• Peak flow zones are based on an individual's optimal lung function or personal-best peak flow. Once that measurement is taken, percentages of that optimal flow measurement determine the zones. The green flow zone, or between 80 and 100 percent of the optimal flow, means the asthma is at manageable levels. The yellow zone, or between 79 and 50 percent, means the asthma is growing worse and may require fast-acting medication along with consultation with a physician. The red zone, or below 50 percent of the optimal flow, indicates a medical alert and the need for immediate medical care.

Benefits

• Asthmatic people can use peak flow meters to reveal what variables trigger asthma attacks. Peak flow meters also help to determine when to seek emergency medical treatment and the effectiveness of the individual's current asthma management plan.