Glossary of COPD-Related Terms

Sometimes it may seem like COPD has its own language! Here is a glossary of common COPD-related terms.

Alpha-1 Antitrypsin Deficiency (Alpha-1)

A genetic form of COPD. In other words, it is passed down from family member to family member. Individuals with this disorder have a low level of a protein (alpha-1 antitrypsin) in the blood which protects the lungs from breathed in toxins.


Medicines given for an infection caused by bacteria. These drugs do not help with infections caused by viruses.


They are a type of medication that works to relax the muscles in the airways allowing them to widen and improve air flow. They are available as rescue relievers and controllers.

Arterial Blood Gas

A blood test that measures oxygen and carbon dioxide in the blood. In this test, a sample of blood is taken from an artery, usually in your arm or wrist.


Millions of tiny sacs at the very ends of the smallest airways/tubes in the lungs. This is where oxygen is absorbed into the blood and carbon dioxide is released from the blood.


This is a type of medication that works to relax the muscles in the airways allowing them to widen and improve air flow. They are available as both maintenance medications that are used daily and quick relief medications that are used as needed.

BiPAP® (Bi-level Positive Airway Pressure)

A breathing machine that provides assistance in breathing through a tight-fitting mask. This machine is often used in the emergency department or hospital if breathing is too difficult.

Bronchial Tubes

The larger airways of the lungs.


Smaller airways of the lungs that lead to the alveoli.


This is a type of medication that works to relax the muscles in the airways allowing them to widen and improve air flow. They are available as rescue relievers and controllers.


Plastic tubing used to deliver oxygen through the nose.

Chest Physiotherapy (CPT)

A treatment performed by respiratory therapists that involved tapping on the chest and/or back to shake mucus loose.

Chronic Bronchitis

A condition in which the bronchial tubes (airways) of the lungs become damaged, inflamed, and swollen. They also produce excess mucus.


Tiny, hair-like fibers that line the bronchial tubes in the lungs. These fibers help move mucus up through the tubes so it can be coughed out.


Medicines that mimic the action of a group of hormones produced by adrenal glands. They reduce the inflammation in your lungs. These medicines can be inhaled or taken by mouth.

CPAP (Continuous Positive Airway Pressure)

The delivery of pressure and air flow to your lungs. CPAP can be used with a small, bedside machine or a ventilator. It helps to keep your airways open.


The muscle that separates the chests cavity from the stomach. The diaphragm is the main muscle used for breathing.


Shortness of breath, or difficult or labored breathing.


A lung condition in which the air sacs of the lungs become damaged and don’t exchange oxygen and carbon dioxide well.


Flare-ups of COPD in which symptoms get worse. Changes in medical treatment may be needed.


Rapid breathing often caused by a worsening lung condition or being nervous and upset.


Too little oxygen in the body.


A portable hand-held device that delivers medication to your lungs.


Providing breathing assistance by putting a tube through the nose or mouth and into lungs. The tube is attached to a machine that does some or all of the work of breathing.

Liquid Oxygen (LOX)

This is oxygen condensed into a liquid state by extreme cold. Liquid oxygen is no longer widely used in the United states.


This is a device that delivers liquid medicines in a fine spray or mist. It requires no special coordination. It is a good method for getting drugs directly into the lungs.

Non-invasive Ventilation (NIV)

Breathing support that is delivered by a mask instead of a tube inserted into your lungs. Bi-Pap is an example of non-invasive ventilation.

Oxygen Concentrator

A machine used for oxygen therapy. It takes oxygen from the air and moves it through a long narrow tube into the nose. Smaller, portable oxygen concentrators are also available.

Oxygen Therapy

A medically prescribed system of providing additional oxygen to the body. It is prescribed when diseased lungs are not able to meet the body’s oxygen needs.

Phosphodiesterase-4 Inhibitor (PDE-4 Inhibitor)

A type of medication that helps control airway inflammation. It may also help decrease COPD exacerbations.


An infection of one or both lungs in which organisms (bacteria, viruses, or fungi) settle in the air sacs of the lungs.

Pulmonary Rehabilitation

A supervised program that includes exercise training, health education, emotional support, and breathing techniques for people with lung diseases.

Pulse Oximetry

A quick, painless test that measures how much oxygen is in your blood. A sensor with a light is placed on your finger or ear. The result of this test may show if you need oxygen therapy.

Sleep Apnea

A condition in which you stop breathing while you sleep. You may also have sleep apnea if your breathing is too shallow during sleep.


A type of lung function test. It measures how much air you are able to get into your lungs. It also measures how fast you can exhale. Spirometry is used to help diagnose lung diseases. It is sometimes used before and after bronchodilator treatments.


Sputum or as it sometimes called phlegm is airway mucus and some saliva (“spit”) which are expectorated or coughed up when clearing the airways.


A medicine that helps open the airways, making breathing easier.


The largest airway in the respiratory system, sometimes called the windpipe.


A breathing tube that is placed in the neck, rather than the nose or mouth. Sometimes used for longer term ventilation.

Resources and Support

The COPD Foundation offers resources such as COPD360social, an online community where you can connect with patients, caregivers and health care providers and ask questions, share your experiences and receive and provide support.