Peak Flow Meter

A peak flow meter is commonly used by a person with asthma to measue the amount of air that can be expelled from the lungs. If the airways become narrow or blocked due to asthma, peak flow values will drop because the person cannot blow air out of the lungs as well. A peak flow meter can be a useful aid in monitoring a person's asthma over time and can also be used to help determine how well a patient's medications are working.

Asthmatic Bronchiole and Normal Bronchiole

Asthma is a disease in which inflammation of the airways causes airflow into and out of the lungs to be restricted. When an asthma attack occurs, mucus production is increased, muscles of the bronchial tree become tight, and the lining of the air passages swells, reducing airflow and producing the characteristic wheezing sound.

Respiratory System Overview

Air is breathed in through the nasal passageways, travels through the trachea and bronchi to the lungs.