Humidifiers are machines that put tiny droplets of water vapor into the air, to help combat breathing problems.
When humidified air is breathed in, the water vapor adds moisture to secretions in the upper airway. This makes the secretions more fluid so it may be easier to cough them up.
Humidifiers work only for the upper airway, that is, the nose, the mouth, and the throat above the vocal cords. Water vapor droplets made by a humidifier do not usually reach the lower airways, which include the trachea, or windpipe, and the lungs.
In the past, steam humidifiers were commonly used. These humidifiers were a danger to children because the humidifier heated water, and many children were accidentally burned by them.
Newer humidifiers, also known as vaporizers, use special energy waves to break water down into a vapor. This results in smaller droplets than were possible with steam humidifiers. Because the vapor is not heated, the system is much safer. The energy waves also kill any bacteria or mold that may be in the water or the machine.
Moisturizing the air may help when the surfaces of the airway are dry. Respiratory illnesses, such as colds and flu, often cause faster and deeper breathing and dry out the airway surfaces. Moist air also seems to soothe irritated, inflamed airways. For a child with a cold and thick nasal secretions, a humidifier can help thin out the secretions and make breathing easier.
For a child with croup, a viral infection of the vocal cords and upper trachea, a humidifier may relieve some of the airway irritation. This can reduce the stridor, a type of harsh breathing noise, and coughing that go along with croup.
The air in modern houses in the wintertime is very dry in most temperate climates. Heating the air to keep it warm tends to reduce its humidity or moisture level. This can be a problem for children who have dry skin. Running a humidifier in the house, especially in the child's room, can help relieve some of the dryness.
In the hospital, a child with croup is often put in a mist tent. This is a plastic enclosure filled with mist from a vaporizer. Mist tents are also used to treat infants with viral infections in the lungs.
If a person with a lower respiratory illness like pneumonia is being treated with oxygen, the oxygen is often humidified. This keeps the oxygen from drying out the membranes of the airway.
A special type of humidifier called a nebulizer can be used to deliver medication to the airway. Nebulizers are often used to treat asthma. They generate smaller water vapor droplets that are able to reach the small airways in the lungs.
Certain medications, such as albuterol, can be dissolved in water and given with a nebulizer. The medications are then able to reach the lungs in greater concentration than if taken by mouth.
A newer approach is to give some antibiotics by nebulizer. It seems to work very well on lower airway infections in children with cystic fibrosis, a serious inherited condition that damages the lungs.