Skip to content

Asthma Health Center

Asthma Glossary of Terms

Font Size
A
A
A

continued...

Bronchodilator: a drug that relaxes the muscle bands that tighten around the airways in asthma. Bronchodilators can also help clear mucus from the lungs.

Bronchospasm: the tightening of the muscle bands that surround the airways, causing the airways to narrow.

Carbon dioxide: a colorless, odorless gas that is formed in the tissues and is delivered to the lungs to be exhaled.

Chronic disease: a disease that can be controlled, but not cured.

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

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.

Contraindication: a reason not to use a course of treatment or medication.

Dander, animal: tiny scales shed from animal skin or hair. Dander floats in the air, settles on surfaces and is a major part of household dust. Cat dander is a classic cause of allergic reactions.

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

Dehydration: excessive loss of water.

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

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

Dust mites: a common trigger for allergies.

Dyspnea: shortness of breath.

Exacerbation: worsening.

Exercise induced asthma : asthma that is made worse when exercising

Exhalation: breathing air out of the lungs

(HEPA) high-efficiency particulate air filter: a filter that removes particles in the air by forcing it through screens containing microscopic pores.

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 lungs 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.

Holding chamber: see spacer.

When Is Your Asthma Worse?

When Is Your Asthma Worse?

Take the WebMD Asthma assessment to get Personalized Action Plan

Start Now

Today on WebMD

Lung and bronchial tube graphic
5 common triggers.
group jogging in park
Should you avoid fitness activities?
 
asthma inhaler
Learn about your options.
man feeling faint
What’s the difference?
 
Madison Wisconsin Capitol
Slideshow
woman wearing cpap mask
Article
 
red wine pouring into glass
Slideshow
Woman holding inhaler
Quiz
 

Pollen counts, treatment tips, and more.

It's nothing to sneeze at.

Loading ...

Sending your email...

This feature is temporarily unavailable. Please try again later.

Thanks!

Now check your email account on your mobile phone to download your new app.

Man outdoors coughing
Article
Lung and bronchial tube graphic
Article
 
10 Worst Asthma Cities
Slideshow
runner
Article
 

WebMD Special Sections