COPD Glossary: 39 Terms to Know

Living with a chronic condition like chronic obstructive pulmonary disease (COPD) means learning a special vocabulary to discuss the ins and outs of your condition.

Understanding these terms may make it easier to communicate with the healthcare professionals you work with during your treatment. It may also help those who care about you and for you to gain a better understanding of what it means to live with COPD.

Even the name COPD provides some information:

• Chronic means long lasting.
• Obstructive means causing an airflow blockage or reduction.
• Pulmonary means relating to the lungs.
• Disease means an illness identified by specific symptoms.

However, the name doesn’t reveal, at least in the U.S., that COPD refers to two different conditions:

• emphysema
• chronic bronchitis

This glossary identifies terms that may be helpful to you as you navigate through your diagnosis, testing, treatment, and more.

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Alpha-1 antitrypsin (AAT)

Also called alpha antiproteinase or AAP.

This is a protein produced in the liver that helps to protect body tissues, including the lungs, from the infection-fighting efforts of the immune system.

Alpha-1 antitrypsin deficiency

This is an inherited condition that causes the lungs to be at greater risk of damage from smoking, pollution, or other irritants. If this runs in your family, you may experience AAT deficiency or be a carrier of the gene. It can be diagnosed through genetic testing. While it can’t be prevented, there are treatments available.

Anticholinergics

Also called cholinergic blockers.

This type of medication may help to relax the airways, allowing for improved airflow and a better ability to clear mucus.

Arterial blood gas (ABG) test

In this test, blood drawn from an artery (usually in the wrist, arm, or groin) is examined for levels of gases (oxygen and carbon dioxide) and pH balance. A blood gas test can help show how well your lungs are able to move oxygen and remove carbon dioxide.

Beta-agonists

This type of medication comes in several forms, including short-acting (SABA), long-acting (LABA), and ultra-long-acting beta-agonists (ultra-LABA).

These work by relaxing the muscles in the airways, which can improve airflow and mucus removal. They are available in different forms but are often used as inhalers in the treatment of COPD.

BiPAP (bi-level positive airway pressure) machine

Also known as BPAP.

This device’s name comes from the fact that it provides two levels of air pressure:

• increased pressure when you breathe in, known as inspiratory positive airway pressure (IPAP)
• reduced pressure when you breathe out, known as expiratory positive airway pressure (EPAP)

These machines consist of a motor connected to tubing and a mask and can be used in a hospital or a home. 

Breathing exercises

In order to manage your symptoms, your doctor may suggest breathing exercises. These can include:

• pursed lip breathing
• huff coughing
• coordinated breathing
• deep breathing
• diaphragmatic breathing

Read more about each of these breathing exercises and how to do them here.

Bronchodilators

These medications work by relaxing the muscles in the airways. This allows them to widen and can improve airflow. Beta 2-agonists, anticholinergics, and xanthine derivatives are types of bronchodilators. They may be fast-acting (also called rescue) or long-acting (also called maintenance). 

Cannula

Plastic tubing that connects to oxygen concentrators or tanks to supply oxygen through the nose.

Clinical trials

These research programs work with people diagnosed with a condition to evaluate a new medical treatment, medication, or device.

They can provide an opportunity to be one of the first to try an up-and-coming treatment option at no cost, but there may be risks and limitations. You can speak with your doctor about whether trials that would be a good fit are available to you.

Compressed oxygen

This describes oxygen that is stored in a tank in a compressed form to be delivered through a mask or cannula. These can be large, in-home units or smaller, portable tanks.

CPAP (continuous positive airway pressure) machine

This type of ventilator provides a steady stream of air at a constant pressure to maintain the flow through narrowed airways. This machine consists of a motor, tubing, and a facial mask worn over the nose or mouth and nose.

Cyanosis

This condition describes a lack of oxygen in the blood that leads to a bluish tint in the skin or mucous membranes. Peripheral cyanosis is seen in the extremities (hands and feet), while central cyanosis affects the entire body.

Diffusion test

This test measures how well your lungs are able to take in oxygen and release carbon dioxide. It’s sometimes called a diffusion lung capacity of carbon monoxide (DLCO) test.

Dyspnea

A term for shortness of breath. This may feel like you’re unable to take in enough air.

Exacerbations

Also known as a flare. This describes more severe symptoms of COPD often caused by a lung infection.

Expectorant

This type of medication helps to thin and loosen mucus in the airways so it can be coughed out more easily.

Hypoxia

This describes a condition in which there is not enough oxygen in the tissues of the body. 

Indoor air quality (IAQ)

This describes the air quality within your home as it relates to your health. Taking steps to remove known irritants or pollutants can improve your lung health. Concerns include tobacco products, some home furnishings, cleaners, appliances, and outdoor sources like radon or pesticides that can affect inside air.

Inhaler

This is a portable, handheld device that allows you to inhale medication directly into the lungs. There are three types of inhalers:

• Metered-dose inhalers (MDI) use a propellant to help push medication into the lungs.
• Dry powder inhalers (DPI) release medication when you breathe in using the device.
• Soft mist inhalers (SMI) create a cloud of medication that you breathe in.

Intubation

If you’re unable to breathe on your own, your doctor may recommend intubation which involves placing a tube through the nose or mouth directly into the lungs. This tube keeps the airway open. In most cases, it’s connected to a ventilator.

Liquid oxygen (LOX)

This is oxygen that is kept in liquid form using extreme cold. If you’re on oxygen therapy, you may use liquid oxygen tanks in the home as they are able to hold more and can be used to refill portable tanks. There are also portable units that patients may use outside the home.

Nebulizer

This machine is used to create a mist from liquid medications. The medication can then be easily inhaled into the lungs. Nebulizers can deliver bronchodilators used to open airways, saline solutions used to break up mucus, or antibiotics used to treat infections.

Orthopnea

This refers to shortness of breath that is noticeable when lying down. This difficulty breathing is typically relieved by moving to a sitting, standing, or propped position.

Oxygen concentrator

This machine pulls oxygen from the air and concentrates it for delivery through a nasal cannula or mask. It may be used for those who are prescribed oxygen therapy.

Oxygen saturation

This is a measure of how much oxygen is being carried in your blood cells. When you’re living with COPD, you and your doctor should discuss the level that’s right for you.

Oxygen therapy

If your lungs aren’t able to meet the oxygen needs of your body, a medical professional may prescribe oxygen therapy, also referred to as supplemental oxygen. This oxygen may be delivered from a tank or concentrator through a nasal cannula or mask, either at home or in a healthcare setting.

Peak expiratory flow rate (PEFR)

Sometimes called peak flow, this is a measurement of how fast you’re able to exhale air from your lungs.

Keeping track of your numbers over time can help you and your doctor identify when your symptoms are well-controlled and when medications are needed.

Postural drainage

This technique involves positioning the body in a way that allows gravity to help drain mucus from the lungs. Learn more about the practice and positions used in this article on postural drainage.

Pulmonary function tests (PFTS)

Sometimes called lung function tests. This describes a series of tests that show how well your lungs are working and the volume of air in the lungs. It also helps in the diagnosis of COPD.

Pulmonary rehabilitation

This is a multilayered program that may include exercise training, nutrition counseling, mental health care, and education in condition management and breathing techniques for people with lung diseases.

Pulmonologist

A pulmonologist (called a respirologist in some countries) is a doctor who specializes in the respiratory system, including the lungs.

Pulse oximetry

Sometimes called pulse ox, this sensor reads how much oxygen is in your blood. It can be used on fingers, forehead, nose, foot, ears, or toes.

There are limitations in their use, as readings may not be as accurate on darker skin, thick skin, use tobacco, have artificial nails, or for other reasons.

Respiratory physiotherapy

This treatment involves working with respiratory therapists who educate, monitor, and manually treat people with breathing problems. Respiratory therapists may perform testing, manually assist in removing mucus from the lungs, and instruct on breathing, coughing, exercise techniques, and positioning.

Sleep apnea

This condition involves a temporary pause in breathing during sleep. many patients with COPD also have sleep apnea.

Spirometry

This lung function test measures how well you breathe out and the largest breath you’re able to take in. During the test, you’ll be asked to place your mouth around a plastic mouthpiece, then be asked to breathe in as much as you can, and then blow as hard and fast as you can.

Sputum

Sputum (sometimes called phlegm) is a type of mucus that is created in the respiratory system and may be released through coughing. The color of sputum ranges from clear to yellow to green to gray.

Ventilator

This machine moves air in and out of your lungs through a mask or breathing tube.

Wheezing

This describes a high-pitched whistling sound when breathing which is caused by narrowed airways.