This is a work in progress. You can find smaller glossaries arranged by subject here.

Allergen - substance causing an allergic reaction. An allergen is an antigen that, in non-allergic people, doesn’t invoke the immune response.

Allergy - excessive immune response to an antigen, or foreign substance, not normally harmful to the body. Allergic symptoms can manifest themselves in the nose (rhinitis), the lungs (asthma), the skin (eczema, uriatica), and the digestive system.

Alveoli - tiny, hollow sacs with thin walls on the ends of the bronchial tubes responsible for gas exchange. Oxygen from the air enters the blood here, and carbon dioxide from the body enters the air through the alveoli in reverse.

Anaphylaxis - life-threatening, whole-body allergic reaction. An individual in anaphylactic shock will experience sudden, severe release of histamine from tissues throughout the body, leading to serious airway restriction, pulmonary edemas, and heart arrhythmias. This type of reaction can cause death within minutes or even seconds, so patients with anaphylactic allergies must carry emergency medication at all times. Research suggests having asthma increases the risk of anaphylaxis in patients with food allergies.

Antibiotic - destroys or stops the growth of bacteria that causes an infection. Antibiotics will not heal viral illnesses like the flu or a cold. Narrow-spectrum antibiotics treat a specific type of bacteria, like that causing strep throat, while broad-spectrum antibiotics treat a variety of bacteria or a drug-resistant strain of one. Recent research suggests broad-spectrum antibiotic use in a baby’s first year increases the risk of developing asthma.
Example: Amoxicillin

Antibody - immune protein, or immunoglobulin, that normally works to protect the body against foreign substances. An allergic person produces antibodies in response to typically benign substances.

Anticholinergic - long-acting maintenance bronchodilator that will help prevent flares but not stop them once started. Anticholinergic inhalers work by stopping the parasympathetic nerve impulse from starting the smooth muscle spasms around the airways.
Example: Atrovent

Antigen - foreign substance that causes the body to mount a defensive immune response. A virus is an example of an antigen. When a virus enters the body of a healthy person, the immune system produces an antibody to bind to the antigen, helping to neutralize and destroy it to make that person healthy again. People with allergies have immune systems that recognize non-harmful substances–pollen, for example–as antigens.

Antihistamine - blocks the effects of histamine, the compound in an allergic reaction that causes symptoms like irritated eyes, itchiness, swelling, runny nose, and post-nasal drip. Antihistamines are available orally or in a spray.
Example: Loratadine (Clarityn)

Beta 2-agonist - bronchodilator available in short-acting form for emergency/quick relief or long-acting form for prevention. Asthma patients use short-acting beta 2-agonist inhalers as their main relief medications during flares. Beta 2-agonists work by binding to the adrenergic receptor to relax the smooth muscles around the bronchioles, preventing spasms.
Example: Ventolin (Albuterol)

Bronchial tubes - two main airways that branch out from the trachea, connecting the trachea to each lung. There are two bronchial tubes, one that leads into the right lung and one that leads into the left.

Bronchioles - tiny airways that branch off the bronchial tubes and end in the alveoli. Bronchospasms, part of an asthma flare, happen here in the smooth muscle fibers of the bronchiole walls. Bronchodilators work to open these airways when constricted.

Bronchodilator - any medicine that opens the bronchioles (airways) by relaxing the smooth muscles around them and clearing excess mucus. During an asthma flare, the smooth muscles spasm and the bronchioles produce more mucus, restricting airflow. Types of bronchodilators include anticholinergics, beta 2-agonists, and theophylline.

Bronchospasm - smooth muscle contractions/tightening around the bronchioles (airways), narrowing them and restricting airflow. Bronchospasms are part of an asthma flare.

Cilia - hairlike structures in the bronchiole tubes that “sweep” mucus out of the lungs. Asthma sufferers produce too much mucus for the cilia to handle, clogging the airways during a flare.

Contact Dermatitis (CD) - skin rash or inflammation that occurs after a person comes in contact with a certain substance. CD can occur with no allergies present when actual skin damage occurs. Strong chemical cleaners, for example, can irritate the skin and cause CD with no involvement of the immune system.

Corticosteroid - reduces lung inflammation and swelling in the lungs. A corticosteroid inhaler works as a preventative medicine because an asthma trigger will not affect healthy lung tissue as severely as inflamed tissue. In a pill or liquid suspension, corticosteroids are used to rapidly reduce inflammation during a severe flare. Often simply called steroid.
Example, inhaled steroid: Fluticasone propionate (Flovent)
Example, oral steroid: Prednisone

Cyanosis - blue-tinted skin, starting around the mouth and resulting from lack of oxygen in the blood. Usually starts to occur when oxygen saturation in the blood drops below 90% but may not be noticeable until 75 to 80%. Cyanosis in conjunction with other symptoms of respiratory distress often indicates a life-threatening flare.

Decongestant - oral medicine that shrinks swollen mucus membranes in the nose, reducing congestion and runny noses. Many asthmatics have problems with excess mucus in the nose as well as in the lungs.
Example: Pseudoephedrine (Sudafed)

Diaphragm - the shelf of muscle at the bottom of your lungs, crucial for breathing. Contractions of the diaphragm allow the lungs to inhale and exhale.

Distress - severely labored breathing requiring emergency care. Asthmatics in distress may experience cyanosis, strained neck and face muscles, posturing, retractions, flared nostrils, wheezing, and/or confusion and restlessness.

Dry powder inhaler (DPI) - a small, handheld plastic container that contains asthma relief medications in powder form. Unlike metered dose inhalers, which require users to push down on the device to release medicine, DPIs use a breath-activated delivery. When a patient takes a deep enough breath on the DPI, it releases the right dose. Children under 5 often can’t activate a DPI.

Dyspnea - shortness of breath, symptom of a major flare. Asthma sufferers sometimes describe a sense of suffocation when they experience this.

Eczema - allergic condition of the skin featuring inflamed patches that can itch, crust, scale, and blister. Also called atopic dermatitis, meaning an allergy-related case of dermatitis that does not require contact to produce the inflammation. Eczema sufferers often also suffer from rhinitis and/or asthma. Eczema, rhinitis, and asthma tend to run in families.

Epinephrine - another name for adrenaline, a hormone. Epinephrine suppressed the immune system and can also act as a bronchodilator. Used to treat anaphylaxis and, less commonly, severe asthma flares during an emergency or when the flare doesn’t respond to other bronchodilators.

Exacerbation - a common medical term meaning a worsening in severity. Also, another term for an asthma flare.

Extrinsic asthma - asthma with allergy-related triggers. Patients who experience flares after breathing in allergens like dust or mold have extrinsic asthma. Also called allergic asthma. Most children have this type of asthma.

Flare - the preferred term for an asthma attack or episode. Flare symptoms include heavy coughing, dyspnea or shortness of breath, wheezing, and chest tightness.

Hay Fever - pollen-triggered rhinitis that occurs in the fall and spring.

High-efficiency particulate air (HEPA) filter - cleans the air by forcing it through filtering screens. The difference between a HEPA filter and others is its level of performance. To qualify as HEPA, a filter must not release more than 3 particles for every 10,000 it captures. While many asthma and allergy patients use free-standing HEPA filters in their homes, no clinical trial has definitively proven their effects on asthma. Some experts say using a HEPA filter screen on a home air conditioner’s output system provides the same level of air purity as a free-standing machine.

Recent research suggests HEPA filters and other products are probably ineffective against the effects of overall indoor dust mite load on asthma.

Histamine - naturally occurring chemical that helps produce the inflammatory immune response. Allergic people produce too much histamine during times when their bodies don’t need it. Histamine reactions can involve runny noses, watery and itchy eyes, asthma flares, skin rashes, and (with food allergies) digestive problems.

Hypoxia - inadequate oxygen in some tissues or the whole body, leading to cyanosis. Severe and/or rapid onset hypoxia can result in unconsciousness, coma, and death.

Immunoglobulin E (IgE) - the antibody responsible for allergic reactions. People with allergies have elevated levels of IgE in their blood.

Immunotherapy - allergy shots, a preventative method of treating allergies. During immunotherapy, an allergist administers a long-term regimen of shots that contain incrementally higher doses of the specific substances that cause allergic reactions in the patient. Over time, the shots desensitize the patient’s immune system to those allergens.

Inflammation - the body’s protective response to injury or harmful substances. Inflammation results in increased blood flow to the site of injury (indicated by swelling and redness), promoting faster healing and flushing out the harmful substance. Problems arise when inflammation occurs unchecked or in places with no injury. People with asthma suffer from chronic inflammation of the lungs.

Intrinsic asthma - asthma with non-allergic triggers. A person with intrinsic asthma might experience flares during respiratory infections or after breathing in smoke or dust. Intrinsic asthma is harder to treat than allergic asthma and is more common in adults than children.

Leukotriene modifier - blocks leukotrienes, a chemical in the body that produces too much mucus and constricts airways. Some patients with mild asthma successfully use leukotriene modifiers, an oral medicine, rather than inhaled corticosteroids for maintenance.
Example: Montelukast (Singulair)

Mast cell stabilizers - preventative inhalers that work by inhibiting mast cells from releasing inflammatory compounds. They work mostly for mild asthmatics, since they are not as effective as corticosteroids in preventing inflammation.
Example: Cromolyn sodium (Intal)

Metered dose inhaler (MDI) - a small plastic container that contains an aerosol receptacle of asthma medication in liquid form. Also called a puffer. When a patient presses the top of the MDI, it releases the correct dose of medication in a mist. The patient breathes this mist into the lungs. Because patients often use MDI’s incorrectly, doctors usually recommend spacers, especially for kids.

Mucus - substance produced by glands in the bronchial tubes, nose, and sinuses. Mucus keeps the airways and lungs clean by trapping particles from the air. The cilia then sweep the mucus to the trachea, where it is coughed up or swallowed. Asthma sufferers produce too much mucus.

Nebulizer - an electrical medicine delivery system that turns liquid asthma medications into a mist. Patients use the nebulizer by breathing the vapor in through a mask or mouthpiece. Because nebulizers are easier to use than inhalers, doctors often prescribe them for young children. One breathing treatment on a nebulizer delivers more medicine than one puff of an inhaler does, but the treatment takes longer and is less portable than an inhaler. (Nebulizers come in home and portable versions.)

Peak flow meter - small, plastic device that measures how many liters per minute (lpm) of air an individual can blow in one fast breath. Lowered peak flow readings are a good early warning signal for asthma sufferers. Keeping track of peak flow can help asthmatics determine when to use bronchodilators and can help doctors prescribe the right dosage of medicines.

Pneumonia - a lung infection that occurs when the alveoli, the small sacs at the ends of the bronchioles that release oxygen into the lungs, become inflamed and filled with fluid. While mild to moderate pneumonia is often treated successfully at home, more severe cases often require hospitalization.

Asthma sufferers have an increased risk of developing pneumonia because the excessive mucus produced during a flare can stay in the bronchii and become infected, especially if the flare is under-treated.

In infants and young children, asthma flares are sometimes misdiagnosed as episodes of pneumonia. Multiple emergency room diagnoses of pneumonia will usually make a pediatrician suspect asthma.

Posturing - shoulders hunched-over while coughing or struggling to breathe during a severe asthma flare. Posturing indicates the need for immediate intervention.

Preventative medicines - used to maintain good lung health and prevent or lessen the severity of asthma flares. Some work as anti-inflammatories, and others are long-acting bronchodilators. No preventative medication will stop an asthma flare once it starts. Leukotriene modifiers, anticholinergics, mast cell stabilizers, and inhaled corticosteroids are preventative asthma medications.

Productive cough - a cough that involves mucus, also called a wet cough. An asthma flare usually involves tight, dry, continuous coughing. While a productive cough helps clear the lungs and airways of irritants or mucus, coughing up discolored or bloody mucus indicates a secondary infection like pneumonia.

Puffer - another term for inhaler.

Quick-relief medicines - those medicines that rapidly force the airways open during an asthma flare. Also called relief, emergency, or reliever medicines. Short-acting beta 2-agonist inhalers are the main reliever medicines.

Rales - the bubbling, whistling, and clicking breath sounds heard through a stethoscope in a pneumonia patient’s lungs. Air moving through airways filled with fluid produces the sounds.

Retractions - during a severe flare, abdominal muscles pull in sharply under the ribcage while struggling to inhale. Retractions indicate the need for immediate intervention.

Rhinitis - allergic response of the nasal passages that produces runny and stuffy noses, itching, and sneezing. Technically, rhinitis refers to inflammation of the nasal mucus membrane and occurs when an allergic person inhales an allergen like pollen.

Spacer - a small holding chamber (with mouthpiece or mask) that connects to an MDI, trapping the medicine an inhaler puffs out. Spacers make inhalers easier to use for children, and they also ensure more efficient medicine delivery for all users, adults and children.

Sputum - another word for mucus or phlegm

Theophylline - a long-acting bronchodilator used as a preventative. Theophylline is related to caffeine and has more serious severe effects than other bronchodilators. Dosage must be monitored very carefully to avoid toxic overdose. Doctors usually prescribe theophylline to enhance other preventatives in severe cases, when other bronchodilators do not work, or when a patient needs to take an oral medicine instead of an inhaled one. Available as a pill or liquid.
Example: Elixophyllin

Trachea - the primary airway that leads into the lungs, also called the windpipe

Urticaria - the clinical term for hives, or raised itchy welts on the skin. Usually, but not always, caused by allergens. Hives are usually temporary, lasting up to a few weeks, but in some rare cases can be severe and chronic. Food allergies often cause hives.

Wheezing - a whistling sound during exhalation, caused by air forced to move through constricted bronchioles (airways) during a flare. Whistling during inhalation is not considered wheezing. Contrary to popular belief, many asthma sufferers don’t wheeze at all.

ABOUT THIS GLOSSARY

This is the mini-dictionary I compiled for myself and originally published as BellaOnline’s asthma editor. I hesitate to use the word *comprehensive* here. That’s a pretty big word. What I’ll say, instead, is this glossary feels comprehensive to me. As with everything else I write on this blog, I don’t claim expert knowledge so much as I pass along what helped me, in case it might help you.