Asthma Glossary
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Airway Obstruction: When we breathe, air passes through our airways (the tubes that carry air into and out of the lungs) to get to our lungs. In someone with asthma, the airways are inflamed, which means that they swell and produce lots of thick mucus. The muscles surrounding the airways also tighten, which makes the already clogged airways even narrower. These narrow, swollen, and mucus-filled airways are obstructed - in other words, they don't let air through as easily as healthy airways. Obstructed airways can lead to symptoms such as coughing, wheezing, and shortness of breath.
Airways: The airways in your lungs are like tubes or straws. The air flows in and out of them so you can breathe. The airways are also called bronchial (pronounced: brong-kee-ul) tubes.
Allergen: An allergen is a substance that's capable of producing an allergic reaction. In some people with asthma, allergens that are breathed in can trigger symptoms such as coughing, wheezing, and shortness of breath. Allergens that commonly cause asthma symptoms include animal dander, dust mites, mold, and pollen.
Allergy-Triggered Asthma: Allergy-triggered asthma is a type of asthma commonly seen in children. Symptoms of asthma in these children are brought on by allergic reactions to things such as dust mites, pollen, or animal dander. Although not all asthma is triggered by allergies, and not all allergies cause symptoms of asthma, an estimated 75% to 85% of children with asthma have some type of allergy.
Asthma: Asthma is a problem with the lungs that causes the airways to swell and produce lots of thick mucus. The muscles surrounding the airways also tend to tighten, which makes the already clogged airways even narrower. This can lead a person to cough, wheeze, and have trouble breathing. People with asthma may be sensitive to certain things, such as viruses, allergies, smoke, and even exercise. Doctors call asthma a chronic condition. This means that people who have asthma will always have the condition, although they may not always have symptoms.
Asthma Action Plan: An asthma action plan is a set of instructions, designed with a doctor, that details how a person with asthma should manage their asthma at home. The plan includes:
- a list of the triggers the bring on person's asthma symptoms and how to avoid them.
- a list of symptoms to watch for and what to do if they happen.
- the names and doses of asthma medicines the person needs and when to use them.
The plan also can include emergency phone numbers, instructions on when to contact the doctor or go right to the ER (emergency department), and where to get emergency care.
When the plan is kept up to date and followed closely, a person's asthma symptoms can be prevented or treated and their asthma can be well-controlled.
Asthma Flare-Up: When symptoms of asthma, such as wheezing, coughing, or shortness of breath, become more severe, more frequent, or both, it's known as an asthma flare-up (also known as an asthma flare, attack, episode, or exacerbation). In a person with asthma, the airways are overly sensitive to certain things (such as allergies, viral infections, cold air, exercise, and smoke) that can "trigger," or bring on, an asthma flare-up.
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Bronchial Tubes: When a person breathes, air taken in through the nose or mouth then goes into the trachea (windpipe). From there, it passes through the bronchial tubes, into the lungs, and finally back out again. The bronchial tubes, which branch into smaller tubes called bronchioles, are sometimes referred to as bronchi or airways. People with asthma have bronchial tubes that are inflamed. This means that the airways swell and produce lots of thick mucus. The bronchial tubes are also overly sensitive, or hyperreactive, to certain things like exercise, dust, or cigarette smoke. This causes the muscles around the bronchial tubes to tighten up. The combination of inflammation and muscle tightening narrows the airways and makes it difficult to breathe.
Bronchoconstriction: The airways (the tubes that carry air into and out of the lungs) are surrounded by a type of muscle called smooth muscle. In people with asthma, these muscles often tighten in reaction to certain things. When this happens, the airways become narrower, which blocks the flow of air and makes it harder to breathe. This narrowing of the airways is known as bronchoconstriction. Along with inflammation of the airways, it leads to symptoms such as coughing, wheezing, and shortness of breath.
Bronchodilator: Bronchodilators are medications commonly used by people with asthma. They relax the muscles that surround the airways and allow the airways (the tubes that carry air into and out of the lungs) to open up. Some bronchodilators act quickly to stop asthma symptoms (such as coughing, wheezing, or shortness of breath) that are often caused by narrowed airways. Known as rescue, quick-relief, or fast-acting medications, these bronchodilators are meant to be used when a person first notices symptoms, but their effect doesn't last long. Other bronchodilators, known as controller medications, are longer acting and are used to control, or prevent, asthma symptoms.
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Controller Medicines (also called Maintenance Medicines or Long-Term Control Medicines): Many people with asthma need to take long-term control medicine every day to control their asthma and prevent symptoms. Most of these work by easing inflammation of the airways; others work by relaxing the airways and making them wider. Long-term control medicines are slow acting, which means they can take days or even weeks to begin working. They don't provide immediate relief of symptoms and shouldn't be used when treatment is needed quickly. This requires faster-acting medicines (known as quick-relief medicines) that can work right away.
Corticosteroids: Corticosteroids are medications commonly used by people with asthma. They work by reducing airway inflammation. They're known as controller medications (also called preventive or maintenance medications) because they control the condition overall and prevent the symptoms from developing. Controller medications are slow acting, meaning they can take days or even weeks to begin working. Because they can't provide immediate relief of symptoms, corticosteroids shouldn't be used when an effect is needed quickly. This requires faster-acting medications (known as rescue medications) that can work on the spot.
Cough: A cough is a reflex that helps your body clear your throat and lungs. A cough is a common symptom in people who have asthma (although it can occur for many other reasons, like when you have a cold). People who have asthma may cough because their airways are irritated (narrow and swollen). For some people, coughing may be the only clue that they have asthma. The coughing may happen only at night or while exercising.
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Dander (also called Animal Dander): All warm-blooded animals shed tiny flakes from their skin called dander (it's like dandruff in humans, but much harder to see). When someone is allergic to animals, dander could be causing the problem. Pet dander can be trouble for people who have asthma because if they're allergic to dander, it can make breathing problems worse.
Dust Mites: Dust mites are microscopic bugs that live in household dust. They work their way into soft places like pillows, blankets, mattresses, and stuffed animals. Many people with asthma are allergic to dust, but it's the droppings produced by the mites in the dust along with the body fragments of dead dust mites, that really cause allergic reactions. When breathed in, these can lead a person to develop allergy or asthma symptoms.
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Exercise-Induced Asthma: Some people have asthma symptoms (such as coughing, wheezing, or trouble breathing) only when they're playing sports or being active. This type of asthma is known as exercise-induced asthma. Being active may be the only cause of their breathing trouble, or it can be just one trigger. People with exercise-induced asthma need to see a doctor. But once they get treatment, they usually can be active and do sports like anyone else. In fact, more than 10% of Olympic athletes have exercise-induced asthma that they've learned to control.
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Histamine: Histamine — a chemical found in some of the body's cells — causes many of the symptoms of allergies, such as a runny nose or sneezing. When a person is allergic to a particular substance, such as a food or dust, the immune system mistakenly believes that this usually harmless substance is actually harmful to the body. In an attempt to protect the body, the immune system starts a chain reaction that prompts some of the body's cells to release histamine and other chemicals into the bloodstream. The histamine then acts on a person's eyes, nose, throat, lungs, skin, or gastrointestinal tract, causing allergy symptoms.
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Immunoglobulin E (IgE): Many people have allergy-induced asthma, which means that their asthma symptoms are triggered by allergic reactions. These people have high levels of an allergy-causing antibody (a type of immune protein in the body) called immunoglobulin E (IgE). When they inhale something that they are allergic to, it attaches to the IgE, which then starts a chain of events leading to symptoms of allergies and asthma.
Immunotherapy: Immunotherapy, also known as allergy shots, is a form of treatment used for certain allergies. It can also be helpful in some cases of asthma in which symptoms are triggered by allergies and aren't helped by medications or avoidance of allergens (allergy-causing substances). Immunotherapy involves multiple injections of an allergen over the course of several years. This slowly builds up the body's tolerance to that allergen, which means that the allergic reaction to that specific allergen will eventually decrease in severity.
Inhaler: Inhalers are portable handheld devices that deliver medication — in a form that the person breathes in — directly to the lungs, unlike a pill or liquid that's swallowed. There are two kinds of inhalers: metered dose inhalers (MDIs), also known as puffers, which deliver the medicine in a mist or spray form, and dry powder inhalers (DPIs), which deliver the medicine in a fine powder form.
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Lung Function Tests: Lung (or pulmonary) function tests are a variety of tests that measure how well a person breathes. They can be used to help diagnose asthma, as well as to assess the severity of a person's asthma and how effectively it's being managed. One example of a lung function test is called spirometry, which involves breathing into a device that records how much and how quickly air can be breathed out following a deep breath in.
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Nebulizer: A nebulizer is an electrically powered machine that turns liquid medication into a mist so that it can be breathed directly into the lungs through a face mask or mouthpiece. People with asthma can use a nebulizer to take their medications.
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Peak Flow Meter: A peak flow meter is a portable handheld device used to measure how well a person with asthma can blow air out of the lungs. (Asthma narrows the airways, making breathing difficult.) The person blows into the meter and then checks the reading. Some people with asthma use a peak flow meter at home to see how well their asthma is being controlled. The meter can tell if the airways are getting narrow even before symptoms start. Peak flow measurements can help people with asthma work with their doctor to identify approaching asthma flare-ups, develop an asthma treatment plan, and know when to get medical care.
Pollen: Pollen is a fine powder produced by certain plants when they reproduce. During the spring, summer, and fall seasons, it's released into the air and picked up by the wind, which brings it to other plants to fertilize them. Inside of these pollen grains are proteins that commonly cause allergic reactions (such as sneezing, runny nose, and itchy eyes) when breathed in. The pollen that's most often responsible for causing allergies comes from grasses, trees, and weeds. Many people with asthma are allergic to pollen. When they breathe it in, it can trigger their asthma symptoms.
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Rescue Medicines (also called Quick-Relief or Fast-Acting Medicines): Rescue medicines are a type of asthma medicine used to relieve symptoms (such as wheezing, coughing, and shortness of breath) or to treat an asthma flare-up. They act quickly to stop symptoms, but the effects aren't long lasting. Most are inhaled and work by relaxing the muscle around the airways (the tubes that carry air into and out of the lungs), making the airways wider and allowing breathing to become easier within minutes. They don't treat the underlying inflammation of the airways — this can require daily treatment with other types of medicines called long-term control medicines. Some people with asthma rely only on rescue medications; others use a rescue medicine with a long-term control medicine to help keep their asthma in check.
Retractions: A retraction is a medical term for when the area between the ribs and in the neck sinks in when a person with asthma attempts to inhale. Retractions are a sign someone is working hard to breathe. Normally, when you take a breath, the diaphragm and the muscles around your ribs create a vacuum that pulls air into your lungs. (It's kind of like sucking liquid through a straw.) But if a person is having trouble breathing, extra muscles kick into action. These muscles cause retractions, which can be seen as the person tries to inhale.
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Spacer: People with asthma often use inhalers (also called puffers) to take their medications. A spacer (also sometimes called a holding chamber) is a device that makes using an inhaler easier and more effective. It attaches to the inhaler on one end and to a mouthpiece or mask on the other end. When the medication from the inhaler is released into the spacer, it's held inside until it's slowly inhaled through the mouthpiece or mask. It doesn't require special coordination that the use of an inhaler alone requires. A spacer also helps deliver the medication to the airways — instead of the mouth and throat — where it can work better with fewer side effects.
Spirometer: A spirometer is an instrument that measures how well your child's lungs are working. To use one, your child breathes into a mouthpiece. The doctor may ask your child to breathe normally or to take a deep breath and blow the air quickly out of their lungs, like blowing up a balloon. A recording device measures the amount of air inhaled or exhaled and how much time each breath took. These measurements can help the doctor find out if your child has a lung problem, such as asthma.
Sulfites: Sulfites are a kind of food preservative that can cause breathing difficulties in some people with asthma. In these people, they're considered an asthma trigger because they bring on asthma symptoms such as coughing, wheezing, or shortness of breath. Some examples of products that contain sulfites include: wine, beer, dried fruits and vegetables, shrimp, and pickles.
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Triggers: During normal breathing, the airways to the lungs are fully open, allowing air to easily move in and out. In a person with asthma, the airways are inflamed and overly sensitive to certain things that wouldn't usually bother others. These can be substances, events, or activities, and they're known as triggers because they "trigger," or bring on, asthma symptoms such as coughing, wheezing, and shortness of breath. Triggers can vary from person to person and from season to season and can change as a child grows older. Some common triggers include: allergens (substances that cause allergies), viral infections, cold air, exercise, and smoke.
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Wheezing: A wheeze is a high-pitched whistling sound made when air flows through narrowed airways in the lungs, usually when people breathe out. Wheezing is a common symptom in people who have asthma, although people can wheeze for reasons other than asthma. A doctor can listen for wheezing through a stethoscope, but sometimes wheezing can be heard even without a stethoscope.