Glossary

action plan - A list of specific instructions drawn up by a health care professional for a person with asthma to follow at home. An asthma action plan includes a normal schedule for asthma medicines, as well as what to do if peak flow readings or asthma symptoms become worse than usual. Asthma action plans are usually split into Zones: Green Zone, Yellow Zone, and Red Zone.

acute - Brief, not ongoing. Usually also implies relatively high intensity. For example, acute asthma symptoms may be ones that last a short time but are worse than a person's usual (see chronic) symptoms.

airways - Hollow tubes to and within the lungs through which air passes during breathing. Airways include the trachea, bronchi, and bronchioles.

allergen - Something that causes an allergic reaction. allergy A type of excessive immune system reaction to a substance in a person's environment. (Can also be called "hypersensitivity reaction.") Allergies can be triggered by eating, touching, or breathing in an allergen. Allergies are often associated with asthma, especially in children.

alveoli - The millions of tiny compartments within the lungs at the ends of the airways. (To imagine the shape, picture bunches of hollow grapes at the ends of hollow stems.) Also called "air sacs." Alveoli are where gas exchange takes place-that is, where the blood picks up oxygen (from the air a person has breathed in) and releases carbon dioxide (to be breathed out). (singular: alveolus)

asprin-sensitive - A type of asthma in which taking aspirin or NSAIDs triggers asthma symptoms. This particular kind of asthma usually starts in adulthood and is often accompanied by polyps (benign growths) in the nose and/or a chronically runny/stuffy nose (rhinitis). Aspirin-sensitive asthma may respond particularly well to leukotriene-modifying drugs.

atopy - The genetically determined tendency to be allergic to things.

attack - See episode.

beta-agonist - Also called beta-2-agonist, beta-adrenergic agonist. Also written ß-agonist, ß2-agonist. The most common type of bronchodilator medication. Albuterol is a beta-agonist. The name beta-agonist comes from the way the medicine works, which is to enhance the stimulation of a certain kind of autonomic nerve (the beta-2 type, as it happens), which is responsible for relaxing the airway smooth muscle (thereby opening the airways).

bronchi - The airways that lead from the trachea to each lung, and then subdivide into smaller and smaller branches. They connect to the bronchioles. The walls of the bronchi are made of smooth lining tissue (called endothelium) over fibrous connective tissue, cartilage, and smooth muscle. They also have many glands to produce mucus. (singular: bronchus)

bronchial provocation testing - See challenge test.

bronchiole - The tiny (all less than 1 millimeter in diameter), branching airways that lead from the bronchi to the alveoli. Bronchioles have elastic fibers and smooth muscle but (unlike bronchi) no cartilage. Most bronchioles also produce mucus.

bronchoconstriction - The reduction in the diameter of the bronchi, usually because of squeezing of the smooth muscle in the walls. This reduces the space for air to go through and can make breathing difficult.

bronchodilator - A medicine that relaxes the smooth muscles of the airways. This allows the airway to open up (to dilate) since the muscles are not squeezing it shut. Bronchodilator medicines do not help inflammation, however.

challenge test - A test done to determine whether or not a person's bronchi are hyperresponsive. The subject breathes in air containing carefully controlled amounts of a substance known to cause bronchoconstriction. (Common substances used include methacholine, histamine, and vaporized salt water.) The bronchi of people with asthma respond to much smaller amounts of the substance than the bronchi of people who do not have asthma. This test is often used to confirm a diagnosis of asthma if there is uncertainty.

chronic - Lasting a long time. Asthma is a chronic illness because it is ongoing and does not just go away in a few days or weeks. control In the context of asthma, the degree to which a person has been able to reduce daily symptoms and acute episodes of the disease while participating fully in normal activities (such as exercising and sleeping through the night). This is usually achieved through taking medications and avoiding triggers.

corticosteroids - A type of medicine used to reduce inflammation. Corticosteroid drugs mimic a substance produced naturally by the adrenal glands. In asthma, corticosteroids are often taken through an inhaler for long-term control. They may also be taken orally or given intravenously for a short time if asthma symptoms get out of control.

DPI - Stands for "dry powder inhaler". This is a variety of device that provides a new way of taking inhaled medicine. The propellants used in regular metered dose inhalers can be bad for the environment. For this reason, drug companies are in the process of switching over to DPI's, which do not use a propellant at all. The medicine is in the form of a very fine powder, which is easily inhaled without the use of an aerosol spray device. There are advantages for patients, too. DPI's can be easier to use, because the patient doesn't have to coordinate the timing of activating the inhaler and breathing in, and the problems of bad taste and unpleasant "feel" are also greatly reduced.

dust mites - Very tiny creatures (microscopic, or just barely visible) that live in the dust in people's homes. They are present both in visible dust (under the bed or behind the couch, for example) and in soft places like pillows, mattresses, blankets, and stuffed animals. They thrive especially when the air is humid. Many people are allergic to dust mites, and trying to reduce the number of them in the home is part of many asthma control plans. (For an extremely extensive discussion of dust mites, see the AAIR dust mite section.

edema - Swelling due to collection of fluid (within cells or tissues).

eosinophil - A type of white blood cell whose major useful role seems to be in protecting against parasitic infections. It is also associated, however, with the inflammation that is at the root of asthma. People with asthma tend to have more eosinophils in their blood and, in addition, have an unusual number of eosinophils "migrate" into their lungs. It is still not entirely clear whether eosinophils cause some of the problems that asthmatics experience, or whether they are just associated with the process without doing damage themselves.

episode - In asthma, a period of markedly worsened symptoms. This may be brought on by exposure to a known trigger or by an upper respiratory infection (a cold), or it may not have a known explanation. An episode may come on all of a sudden or may develop gradually over days. Asthma episodes, at their worst, can be life-threatening, and should always be taken seriously.

episodic - Intermittent, with periods of apparent normal function in between periods of symptoms.

exacerbation - See episode.

extrinsic - A classification of asthma that means about the same thing as "allergy-related". Extrinsic asthma has symptoms triggered by exposure to an allergen. (This term is not used much any more.)

FEV-1 - The "forced expiratory volume in one second". In other words, this is the amount of air you are able to blow out in one second of blowing as hard as you can. This measurement, obtained through spirometry gives your doctor an idea of the level of blockage you have in your airways due to inflammation, mucus, or bronchoconstriction.

FVC - "Forced vital capacity". This is the total amount of air you can blow out after you've taken a deep breath. It is one of the measurements doctors obtain through pulmonary function tests.

GERD - Gastroesophageal reflux disease. GERD is a chronic disorder in which some of the acid and enzymes that belong in the stomach are allowed to get up into the esophagus. This leads to the sensation of "heartburn" and sometimes also an unpleasant sour taste in the mouth. GERD and asthma can make a vicious circle: GERD is more common among people with asthma, and it also seems to make asthma worse in people who have it. Treatment of GERD can lead to an improvement in asthma symptoms.

histamine - A chemical made naturally in the body that is involved in inflammation, particularly inflammation related to an allergic reaction. Antihistamines, as the name suggests, are medicines that block the effect of histamine. (Histamine made in a laboratory is sometimes also used in challenge testing.)

holding chamber - A device much like a spacer, which is also intended to help medicine from an MDI get into the lungs. The difference between a spacer and a holding chamber is that a holding chamber has a special valve on it that allows a person more time to breathe in the medicine (the breath does not need to be coordinated with the puff). In the real world, holding chambers are often called "spacers" also, even though they are slightly different things.

hyperreactivity - Same as hyperresponsiveness, below.

hyperresponsiveness - The "twitchiness" of the airways of people with asthma, resulting in excessive reaction to substances, smells, and activity. Even little things that would have no effect on the airways of nonasthmatic people cause the smooth muscle of the asthmatic's airway to squeeze and squeeze.

inflammation - A complex process in the body involving many types of cells (especially white blood cells) and chemicals (such as cytokines and leukotrienes). Inflammation may be protective or may be harmful. The typical signs of inflammation are redness, swelling, warmth, and pain. Loss of function (partial or complete) is often seen, and some kind of exudate is common. Inflammation of the airways is the main underlying problem in asthma.

inhaled corticosteroid - Anti-inflammatory medicine breathed directly into the lungs. The advantage to this is that the medicine goes directly to where the inflammation is, and has minimal effects on the rest of the body (and therefore fewer side effects than corticosteroids taken orally).

inhaler - See metered dose inhaler.

intrinsic - A classification of asthma that means the asthma symptoms are not caused by exposure to allergens. Aspirin-sensitive asthma is one kind of intrinsic asthma. (The term "intrinsic asthma" is not used much any more.)

intubation - The process of putting a tube down someone's throat into the trachea; the tube is connected to a machine (a respirator, or ventilator) that pushes measured amounts of air into the lungs (and then lets it out again) to help the person breathe. This can save the life of a person having a severe asthma episode but also has many risks and possible complications.

irritant - A substance that triggers asthma symptoms by irritating the airway when breathed in. Examples include cigarette smoke, fumes from a harsh cleaning fluid, or strong perfume. (Allergens are a different type of asthma trigger, which cause symptoms through an allergic reaction rather than by irritation.)

labile - Easily changing, unstable. If your asthma is labile, it means that you can go quickly and unpredictably from being perfectly fine to barely getting enough air.

leukotriene - A type of chemical involved in inflammation. Leukotrienes seem to play a particularly important role in the inflammation associated with asthma. Recently some asthma medicines have been developed that work to reduce leukotrienes or their effects (these are called "leukotriene modifiers" or "leukotriene inhibitors").

LRI - Lower respiratory infection. Some examples include pneumonia, bronchitis, and bronchiolitis.

metered dose inhaler - Often called "MDI". A device that allows delivery of medicine directly into the lungs. The medicine is in the form of a very, very fine powder, and a propellant is used to get the powder out in a cloud to be inhaled. Unfortunately, the propellant used in the standard MDI's is composed of CFC's (chlorofluorocarbons), which are involved in the destruction of the ozone layer. Different types of devices to deliver medicine to the lungs are now being designed, and some are already available to consumers (see DPI). For instructions on use of MDI's (as well as of the newer devices), go to Correct Use of Inhalers and Nebulizers (currently under construction.)

methacholine - A type of chemical used in challenge testing. Everybody's airways respond to it, but the airways of a person with asthma respond much more and at lower doses.

morbidity and mortality - Sickness and death. These words are usually used when looking at the effects of a disease in a population. For example, "asthma causes significant morbidity in this group" means "asthma makes a lot of people in this group sick." "Asthma mortality in this country is unacceptable," means "It is unacceptable if anyone in this country dies of asthma."

mucus - A substance secreted by various tissues in the body (the mucous membranes) made up of water, mucin (a glycoprotein), salts, and some cells. In the lungs, mucus serves to lubricate the insides of the airways and to trap inhaled foreign particles so that they can be coughed out. In asthma, however, an excess of mucus is produced and can actually block airways. Mucus also tends to be thicker and more viscous in asthmatics.

NSAID - Non-steroidal anti-inflammatory drug, generally used to treat mild to moderate pain, especially pain that has a component of inflammation (such as arthritis pain). Some people (about 10%-20% of all asthmatics) have their asthma symptoms triggered by these drugs (along with aspirin). Episodes triggered in this way can be quite severe and even life-threatening. NSAID's include such medicines as ibuprofen (Motrin, Advil), naproxen (Naprosyn, Aleve, Anaprox), and a few related prescription medicines (such as Relafen, Daypro, Feldene, and Indocin).

nebulizer - A machine for getting medicine into the lungs. A nebulizer makes a mixture of liquid medicine and water into a mist that a person then inhales (through a mask or a mouthpiece). Nebulizers are often used for babies and children too small to be able to coordinate using a metered dose inhaler. They are also sometimes used for people having severe asthma symptoms, as many people find it easier to take in the medicine this way when they are having a lot of trouble breathing.

peak flow - The very fastest you can move air by blowing out as hard as you can. This measurement correlates pretty well with FEV-1 (a measurement obtained through spirometry in a doctor's office) but doesn't require expensive equipment and can be obtained easily at home with a peak flow meter.

peak flow meter - A device to measure how hard and fast a person can blow air out. This is an indication of how well the lungs and airways are doing. A peak flow meter is an important part of an asthma home-monitoring plan.

pulmonary function tests - Often called "PFT's". A series of tests done (usually in a lab in a hospital) to determine whether a person has breathing problems, and precisely what those problems are. These are used to differentiate among different diseases and disorders. It is sometimes hard for a doctor to tell just by a regular exam whether a person has asthma or another condition, and pulmonary function tests can help clarify the diagnosis. PFT's do not hurt. They involve things like holding your breath, blowing into a tube as hard as you can, and exercising while wearing a special mask.

reflux - See gastroesophageal reflux disease.

residual volume - The amount of air left in your lungs when you have exhaled as far as you can. (Your body doesn't let you exhale all the air in your lungs, because then your lungs would collapse.) This is one of the measurements obtained in pulmonary function testing.

respirator - See intubation.

severity - How bad or serious a disease is. In asthma, severity is generally broken up into four categories: mild intermittent, mild persistent, moderate persistent, and severe persistent. (Some experts also include a category for "severe intermittent" for those unusual people who most of the time have no asthma symptoms at all but occasionally have very serious or life-threatening asthma episodes.) Just as we do not know what causes asthma, we do not understand why individuals differ so much one from another in asthma severity.

sinusitis - An inflammation of the sinuses (hollow spaces in the bone of the cheeks and forehead) due to infection. Common symptoms of sinusitis include pain in the face, colored (not white or clear) secretions from the nose, and headache. A lot of people who have asthma also have problems with recurrent sinusitis. There is some evidence that a flare-up of sinusitis can trigger a worsening of asthma symptoms, but this is still not certain.

smooth muscle - Sometimes called involuntary muscle. A type of muscle found many places in the body, including the walls of the airways. (It is called smooth muscle simply because of how it looks under a microscope, to distinguish it from striated muscle, which is what makes up the heart as well as voluntary (skeletal) muscle.)

spacer - A device usually consisting of a plastic chamber that attaches to a metered dose inhaler on one end, with a mouthpiece on the other end. A spacer is intended to help medicine from a metered dose inhaler get into the lungs. Without a spacer, much of the medicine in an inhaler "puff" gets deposited on the tongue or in the back of the throat.

spirometry - The most commonly used pulmonary function test, done in a doctor's office or pulmonary function laboratory. The machine used measures how fast a person can blow out air, and how much air is blown. The results of this test include the FEV-1, the peak flow, and the FVC.

status asthmaticus - A severe episode of asthma that is not helped (or only partially helped) by inhaled bronchodilators, and that threatens a person's ability to breathe altogether. May require intensive bronchodilator therapy, systemic corticosteroids (oral or IV), or even intubation.

steroids - A general term for a wide variety of chemicals, natural and synthetic. In the context of asthma, "steroids" is usually a shorthand way of referring to corticosteroid medicines (taken to reduce asthma inflammation). Other steroids, including natural and synthetic sex hormones (such as the testosterone-like compounds sometimes used by athletes to build their muscles), are generally unrelated to asthma.

support group - A group of people all sharing a certain problem or concern (such as having asthma, or having a child with asthma) who meet to discuss how they are dealing with it. Support groups provide emotional support by decreasing a person's sense of isolation and can also provide practical advice, since other members of the group have experience confronting similar challenges. Social workers associated with local hospitals or clinics should have information on what support groups are available in your area.

systemic - Relating to or affecting the body as a whole (rather than one specific organ or part).

total lung capacity - The total amount of air in the lungs when a person has breathed in as far as possible. This is one of the measurements obtained in pulmonary function testing.

trachea - The largest breathing tube in the body, passing from the throat down to the chest (where it connects to the two bronchi leading to the lungs).

trigger - Anything that causes asthma symptoms to worsen in a given person. Different things are triggers for different people. Common triggers include exercise, cigarette smoke, pollen, dust, cold air, and aspirin/NSAIDs. Upper respiratory infections are perhaps the most common trigger for asthma symptoms.

URI - Upper respiratory infection. Medical term for a "cold".

ventilator - See intubation.

wheeze - A breathing sound that may be squeaky, whistling, or musical. Wheezes are often (but not always) a symptom of asthma. (Some people have asthma but never wheeze, and some people wheeze for reasons other than asthma.) Wheezes are due to air passing through a narrowed opening and are therefore usually accompanied by difficulty breathing.

zones - The way that asthma signs and symptoms are classified in an asthma action plan. Usually, the zones are the Green Zone (all is well, continue with regular medicines and activities); the Yellow Zone (trouble starting; follow doctor's instructions for Yellow Zone); and Red Zone (DANGER! Get to the emergency room as quickly as possible). These are determined by symptoms and peak flow readings. under construction.