A - E

Acute: sudden

Allergen: a substance (such as a food or pollen) that your body perceives as dangerous and can cause an allergic reaction.

Allergy: abnormal reaction to a stimulus called an allergen. Allergy refers to the abnormal response of the airways to inhaled stimuli, such as pollen, or to consumed items, such as foods, that may cause unusual airway reactions and lead to bronchospasm.

Alpha1-antitrypsin (AAT): (also called alpha antiproteinase or AAP). A protective material produced in the liver and transported to the lungs to help combat inflammation. Deficiency states occur as the result of hereditary defects.

Alveoli: thin-walled, small sacs located at the ends of the smallest airways in the lungs where the exchange of oxygen and carbon dioxide takes place.

Antibiotic: medication used to treat infection caused by bacteria. Antibiotics do not protect against viruses and do not prevent the common cold.

Anticholinergics: (also called cholinergic blockers or “maintenance” bronchodilators). This type of medicine helps open (dilate) the bronchial tubes (airways) to help move more air easily into and out of the lungs. Anticholinergics also help clear mucus from the airways. As the airways open, the mucus moves more freely and can therefore be coughed out more easily. Anticholinergics work differently and more slowly than fast-acting bronchodilators.

Antihistamine: medication that prevents symptoms of congestion, watery eyes, sneezing, and itchy, runny nose by blocking histamine receptors.

Anti-inflammatory: medication, such as prednisone, aspirin or steroids, that reduces inflammation and swelling.

Apnea: absence of breathing for more than 10 seconds. See also sleep apnea.

Arterial blood gas test: a blood test that measures oxygen and carbon dioxide in the blood.

Atelectasis: partial or complete collapse of the lung, usually due to a blockage of the air passages with fluid, mucus or infection. Symptoms include dry cough, chest pain and mild shortness of breath.

Asthma, chronic: a disease of the air passages 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 shortness of breath, wheezing and excess mucus production.

Bacteria: infectious organisms (germs) that may cause bronchitis or pneumonia.

BIPAP (bi-level positive airway pressure) machine: a breathing machine that uses two pressure levels (inspiratory and expiratory) to provide breathing assistance. This machine is often used for patients with sleep apnea or respiratory failure.

Black pigment: the material that gives damaged human lungs a black and sooty appearance.

Blebs and bullae: localized destruction of portions of the lungs that may compress otherwise useful lung tissues.

Breathing rate: the number of breaths per minute.

Bronchial tubes: branches of the airways (air passages) in the lungs.

Bronchioles: the smallest branches of the airways in the lungs. They connect to the alveoli (air sacs).

Bronchitis, chronic: irritation and inflammation of the lining of the bronchial tubes. The irritation causes coughing and excess amounts of mucus in the airways which can lead to difficulty breathing. Bronchitis is considered chronic when the person has a productive cough (coughs up mucus) and shortness of breath that lasts at least three months each year for at least two years in a row.

Bronchodilator: medication used to relax the muscle bands that tighten around the airways to increase air flow. Bronchodilators also help clear mucus from the lungs.

Bronchodilators, fast-acting: (also called “rescue” or “quick relief” medications). These medications quickly relax muscles that tighten around the airways, making the airways wider, breathing easier, and shortness of breath reduced.

Bronchodilators, long-acting: also called (“maintenance” medications). These medications prevent airway spasms throughout the day and night; they take effect more slowly than fast-acting bronchodilators, but work for a longer period of time.

Bronchospasm: the sudden tightening of the bands of muscle that surround the airways, causing the airways to become narrower. Bronchospasm may result in wheezing.

Cannula: a small plastic tube used to supply extra oxygen through the nose.

Carbon dioxide: a colorless, odorless gas that is formed in tissues of the body and is delivered to the lungs for removal.

Carcinogen: cancer-causing substance.

Chronic: continuing over a certain period of time; long-term.

Cilia: hair-like structures that line the airways in the lungs and help to clean out the airways.

CPAP (continuous positive airway pressure) machine: A breathing machine that provides pressure to keep the upper airways open during breathing. This machine is often used for patients with obstructive sleep apnea.

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.

Closed mouth technique: a method for inhaling medicine from a metered dose inhaler. The open mouth technique is the preferred method. (See open mouth technique)

Contraindication: any condition which indicates that a particular course of treatment (or exercise) would be inadvisable or cause harm.

Controlled coughing: a technique in which the cough comes from deep within the lungs and has just enough force to loosen and carry mucus through the airways without causing them to narrow and collapse. Controlled coughing saves energy and oxygen.

COPD (chronic obstructive pulmonary disease): COPD is a general term for several lung diseases that includes chronic bronchitis, emphysema and chronic asthma. COPD adds to the work of the heart, since the amount of oxygen that goes to the blood may be reduced. The two primary causes of COPD are cigarette smoking and alpha1 antitrypsin deficiency. Air pollution and occupational dusts may also contribute to COPD, especially if the person exposed to these substances is a smoker.

Cor pulmonale: enlargement of the right side of the heart. Cor pulmonale weakens the heart and causes increased shortness of breath and swelling in the feet and legs. Patients who have chronic COPD with low oxygen levels may develop this condition.

Decongestant: Medication that shrinks swollen nasal tissues to relieve symptoms of nasal swelling, congestion and mucus secretion.

Diaphragm: most efficient breathing muscle, located at the base of the lungs.

Diaphragmatic breathing: method of breathing which helps you use the diaphragm correctly so you use less effort and energy to breathe.

Diffusion capacity: a measurement of how much oxygen is carried from your lungs into your bloodstream.

Dry powder inhaler (DPI): a device for inhaling respiratory medications that come in powder form.

Durable Power of Attorney for health care: a legal document that authorizes another person to make health-care decisions for you if you became physically or mentally unable to make these decisions yourself.

Dyspnea: shortness of breath.

Edema: swelling that may occur in the ankles, feet or legs.

Electrocardiogram (EKG): a tracing of the heart’s electrical activity. Can show heart strain and heart disease.

Emphysema: the destruction, or breakdown, of the walls of the alveoli located at the end of the bronchial tubes. The damaged alveoli are not able to exchange oxygen and carbon dioxide between the lungs and the blood. The bronchioles lose their elasticity and collapse during exhalation, trapping air in the lungs. The trapped air keeps fresh air and oxygen from entering the lungs.

Exacerbation: worsening.

Expectorant: medication that helps to thin mucus in the airways so it can be coughed out more easily. These medications should be taken with at least 8 ounces of water.

F - L

Flutter valve: see mucus clearing device

Heart failure: a condition caused by weakening of the heart muscle. The heart is strained and can not pump enough blood. Fluid can build up in the lungs and other parts of the body. Symptoms can include shortness of breath and swelling of the legs, ankles and feet. (HEPA) high-efficiency particulate air filter: a filter which removes particles in the air by forcing it through screens containing microscopic pores.

High blood pressure: a condition (that usually has no symptoms) involving higher than normal pressure of the blood against the blood vessels. High blood pressure increases the risk of developing heart disease, a heart attack and a stroke.

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 sinus membranes 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.

Hypoxia: insufficient oxygen in the tissues, even though blood flow is adequate.

Incentive spirometer: a device that encourages deep inspiration to expand the lungs and improve cough effectiveness.

Inflammation: a response in the body that may include swelling and redness.

Inhaler: See metered dose inhaler (MDI)

Inspiration: breathing air into the lungs; inhalation.

Intubation: placing a tube in the trachea (wind pipe) to enable artificial breathing; can be a lifesaving procedure.

I/E ratio: inhalation/exhalation ratio, or the relative length of inhalation (breathing in) compared to exhalation (breathing out). Irritant: substance that is not an allergen (see allergen) but can cause a reaction in the airways or damage the lungs.

Leukotriene modifier: medication 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 are also helpful in improving airflow and reducing some COPD symptoms.

Living Will: a legal document in which you can state what kind of medical care you desire to receive or what life-support procedures you would like to withhold if you became physically or mentally unable to communicate your wishes.

Lung volume: See total lung capacity

Lung volume reduction surgery: surgery in which damaged areas of the lungs are removed so the remaining portion of the lungs can function better. Lung volume reduction surgery is performed only for people with certain types of COPD, and after careful testing and evaluation.

Lung transplantation: a surgical procedure in which a healthy lung from a donor replaces the recipient’s unhealthy lung. Lung transplant as a treatment option for COPD is reserved for carefully selected patients.


Maximal oxygen uptake: a person’s highest rate of oxygen consumption. This measurement is usually expressed in milliliters of oxygen per kilogram of body weight per minute.

Medical history: a list of a person’s previous illnesses, present conditions, symptoms, medications and health risk factors.

Medical referral: a doctor’s recommendation that a patient see a qualified medical professional, often a specialist, to review their health status and determine whether medical treatment is needed or whether a particular course of exercise and/or diet change is safe.

Metabolism: the body’s use of oxygen and food to produce energy.

Metered dose inhaler (MDI): small aerosol canister placed in a plastic container that releases a mist of medication when pressed down from the top. This medication can be breathed into the airways. Many COPD medications are taken
using a MDI.

Mucolytic agent: medication that thins mucus secretions.

Mucus: a material produced by glands in the airways, nose, sinuses and elsewhere in the body. Mucus cleans and protects certain parts of the body such as the lungs.

Mucus clearing device: a device used to loosen mucus in the airways so it can be coughed up more easily.

Nasal cannula: a light-weight tube with two hollow prongs that fit just inside the nose. Nasal cannulas are used to deliver oxygen.

Nasal spray: medication used to prevent 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) medications such as Albuterol and Atrovent. 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.

Non-steroidal: medication that is not a steroid. Also see steroid.

Open mouth technique: effective method for inhaling medicine from a metered dose inhaler. See closed mouth technique.

Orthopnea: difficulty breathing related to body position, especially shortness of breath while lying on the back. This is often treated by propping the person’s head on two or more pillows while lying down.

Oxygen: the essential element in the respiration process to sustain life. This colorless, odorless gas makes up about 21 percent of the air. Oxygen may be prescribed if your lungs are not getting enough oxygen to your blood. Breathing prescribed oxygen increases the amount of oxygen in your blood, reduces the extra work of the heart and decreases shortness of breath.

Oxygen, compressed: a form of prescribed oxygen that is stored in a tank in gas form. A flow meter and a regulator are attached to the tank to adjust the oxygen flow. The compressed oxygen system is generally prescribed when oxygen is not needed all the time, such as only when walking or performing physical activity.

Oxygen, liquid: At very cold temperatures, oxygen changes from a gas to a liquid. When liquid oxygen is warmed, it becomes a gas so that it can be delivered to you. A liquid oxygen system includes a large stationary unit that stays in the home. It also includes a small, portable canister (weighing from 5 to 13 pounds) that can be filled from the stationary unit for trips outside the home.

Oxygen concentrator: an electric oxygen delivery system about the size of a large suitcase. The concentrator extracts some of the air from the room and separates the oxygen from other gases in the air. Oxygen is then delivered to you through a nasal cannula. An oxygen concentrator may be recommended if you need oxygen all the time or while sleeping.

PEP valve: See mucus clearing device

Peak expiratory flow rate: a test used to measure how fast air can be exhaled from the lungs.

Personal best peak expiratory flow (PEF): the highest peak flow number a person can achieve over a 2- to 3-week period when symptoms are under good control. The personal best PEF is the number to which all other peak flow readings will be compared.

Pharynx: the back of the throat through which air passes when you inhale.

Pneumonia: a sudden infection of localized areas of the lungs. Pneumonia often accompanies bronchitis.

Pollen: a fine, powdery substance released by plants and trees.

Positive expiratory therapy valve: see mucus clearing device

Postural drainage: positioning oneself in certain postures to allow gravity to help drain mucus or phlegm from the lungs.

Productive cough: a “wet” cough that may involve coughing up mucus.

Puffer: another term for inhaler or metered dose inhaler.

Pulmonary function tests (PFTS): a series of tests that measure how well air is moving in and out of the lungs and carrying oxygen to the blood stream.

Pulmonary hypertension: a rare lung disorder in which the arteries in the lungs have become narrowed, making it difficult for blood to flow through the vessels. Pulmonologist: a doctor who specializes in caring for people with lung diseases and breathing problems.

Pulse oximetry: a non-invasive test in which a device that clips on the finger measures the oxygen level in the blood.

Pursed lip breathing: a method of breathing through pursed lips (as if you were blowing on a whistle) to improve breathing patterns.

Relapse: the return of signs and symptoms of an illness after a period of improvement.

Residual volume: the volume of air remaining in the lungs, measured after a maximum expiration.

Respiration: the process of breathing which includes the exchange of gases in the blood (oxygen and carbon dioxide). See inhalation and exhalation.

Respiratory failure: the sudden inability of the lungs to provide normal oxygen delivery or normal carbon dioxide removal.

Respiratory therapist: a health care professional who specializes in assessment, treatment and education for people with lung diseases. Respiratory therapy department: a hospital department that provides therapies and treatments to patients who have cardiopulmonary problems.

Pulmonary rehabilitation: a program that can help you learn how to breathe easier and improve your quality of life. It includes treatment, exercise training, education and counseling.

Sleep apnea: a sleep disorder in which a person’s breathing stops in intervals that may last from 10 seconds to a minute or longer. When an apneic event occurs, air exchange may be impaired.

Spacer: a tube-like device used with a metered dose inhaler. The spacer makes it easier to coordinate pressing on the inhaler and breathing in the medicine.

Spirometry: see total lung capacity test

Sputum: mucus or phlegm.

Steroid: medication that reduces swelling and inflammation. Comes in pill and inhaled forms.

Supplement: nutritional: drinks that can be used in addition to meals to increase intake of calories and nutrients.


Theophylline agents: (also called “maintenance” or “long-term control” bronchodilators). These agents open airways, prevent and relieve airway spasms, and prevent night-time cough and shortness of breath.

Thorax: the muscular and bony structure of the chest.

Tidal volume: the quantity of air inhaled and exhaled in one respiratory cycle during regular breathing.

Total lung capacity test: a test that measures the amount of air in the lungs after a person has breathed in as much as possible.

Trachea: the main airway (windpipe) supplying air to both lungs.

Tracheostomy: a surgical opening made when necessary in the main airway, the trachea.

Vaccine: an injected medication that may stimulate the immune response to protect a person from an infection.

Ventilator: the proper term for a breathing machine used to treat respiratory failure and help support breathing.

Vital capacity: maximal breathing capacity; the amount of air that can be expired after a maximum inspiration.

Wheezing: the high-pitched whistling sound of air entering or leaving narrowed airways.