Many people with asthma have a nebulizer as part of their treatment plan. A nebulizer is a machine that takes a liquid asthma medication and turns it into an aerosol mist via either pressurized air or ultrasonic sound waves. Then the medicine travels through a tube, from where you breathe it into your airways.

Nebulizers are used commonly in infants and young children, who are too young to use a metered dose inhaler reliably. But sometimes older children and adults can benefit from using a...