Asthma Glossary of Terms
Anticholinergics: (also called cholinergic blockers or “maintenance” bronchodilators). This type of medicine relaxes the muscle bands that tighten around the airways. This action opens the airways, letting more air out of the lungs to improve breathing. Anticholinergics also help clear mucus from the lungs.
Asthma: a disease of the airways or branches of the lung (bronchial tubes) that carry air in and out of the lungs. Asthma causes the airways to narrow, the lining of the airways to swell and the cells that line the airways to produce more mucus. These changes make breathing difficult and cause a feeling of not getting enough air into the lungs. Common symptoms include cough, shortness of breath, wheezing, chest tightness, and excess mucus production.
Beta2-agonists: a bronchodilator medication that opens the airways of the lung by relaxing the muscles around the airways that have tightened (bronchospasm). These medications may be short acting (quick relief) or long acting (control) medications. Short acting beta2 agonists are the drugs used to relieve asthma symptoms when they occur.
Clinical trials: research programs conducted with patients to evaluate a new medical treatment, drug, or device. The purpose of clinical trials is to find new and improved methods of treating different diseases and special conditions.
Histamine: a naturally occurring substance that is released by the immune system after being exposed to an allergen. When you inhale an allergen, mast cells located in the nose and lungs release histamine. Histamine then attaches to receptors on nearby blood vessels, causing them to enlarge (dilate). Histamine also binds to other receptors located in nasal tissues, causing redness, swelling, itching, and changes in the secretions.
Hydrofluoroalkane Inhaler (HFA): small aerosol canister in a plastic container that releases a mist of medication when pressed down from the top. This drug can be breathed into the airways. Many asthma medications are taken using an HFA, which was formerly called a “metered dose inhaler.”
Leukotriene modifier: drug that blocks chemicals called leukotrienes in the airways. Leukotrienes occur naturally in the body and cause tightening of airway muscles and production of excess mucus and fluid. Leukotriene modifiers work by blocking leukotrienes and decreasing these reactions. These medications may also be helpful in improving airflow and reducing some symptoms of chronic obstructive pulmonary disease (COPD).
Mold: parasitic, microscopic fungi (like those in the genus Penicillium that produce penicillin) with spores that float in the air like pollen. Mold is a common trigger for allergies and can be found in damp areas, such as the basement or bathroom, as well as in the outdoor environment in grass, leaf piles, hay, mulch, or under mushrooms.
Nasal spray: medication used to help prevent and treat nasal congestion or nasal allergy symptoms. Available by prescription or over-the-counter in decongestant, corticosteroid, or salt-water solution form.
Nebulizer: a machine that changes liquid medicine into fine droplets (in aerosol or mist form) that are inhaled through a mouthpiece or mask. Nebulizers can be used to deliver bronchodilator (airway-opening) drugs such as albuterol and Atrovent, as well as anti-inflammatory or steroid medicines (Pulmicort Respules). A nebulizer may be used instead of a metered dose inhaler (MDI). It is powered by a compressed air machine and plugs into an electrical outlet.
Peak flow meter: a small hand-held device that measures how fast air comes out of the lungs when a person exhales forcefully. This measurement is called a peak expiratory flow (PEF) and is measured in liters per minute (lpm). A person’s PEF may drop hours or even days before asthma symptoms are noticeable. Readings from the meter can help the patient recognize early changes that may be signs of worsening asthma. A peak flow meter can also help the patient learn what trigger their symptoms and understand what symptoms indicate that emergency care is needed. Peak flow readings also help the doctor decide when to stop or add medications.
Personal best peak expiratory flow (PEF): the highest peak flow number a person can achieve when symptoms are under good control. The personal best PEF is the number to which all other peak flow readings will be compared. In children, peak expiratory flow rates are based on how tall the child is. Therefore, the personal best peak expiratory flow will change as growth occurs. A child’s personal best peak expiratory flow should be redetermined approximately every 6 months or when a growth spurt has occurred.
Pollen and mold counts: a measure of the amount of allergens in the air. The counts are usually reported for mold spores and three types of pollen: grasses, trees, and weeds. The count is reported as grains per cubic meter of air and is translated into a corresponding level: absent, low, medium, or high.
Respiration: the process of breathing which includes the exchange of gases in the blood (oxygen and carbon dioxide), the taking in and processing of oxygen, and the delivery of carbon dioxide to the lungs for removal. See inhalation and exhalation.
Spacer: a chamber that is used with a metered dose inhaler to help the medication get into the airways better. Spacers also make metered dose inhalers easier to use; spacers are sometimes called “holding chambers.”