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A 47-year-old member asked:

Bronchoconstriction (asthma/copd) affects breathing out during expiration, but not breathing in during inspiration, how come?

1 doctor answer2 doctors weighed in
Dr. William Galli
Internal Medicine - Pulmonary Critical Care 28 years experience
Dynamic collapse: This is a fancy term of when airway pressure is more on the outside of your airways and collapses as you exhale. This pressure difference happens at different stages of exhalation in copd. With asthma there is narrowing of your airways from inflammation so this constricts the diameter and makes this worse. All due to airway pressure and "equal pressure point". Hope this helps!

Similar questions

A 46-year-old member asked:

I have bronchoconstriction (asthma/copd) affects breathing out during expiration, but not breathing in during inspiration..Why, what to do?

2 doctor answers2 doctors weighed in
Dr. Mark Avdalovic
Pulmonary Critical Care 26 years experience
Bronchodilators: To improve the flow of air you need to use bronchodilators which open the airways and allow the air to pass through more easily. There are many inhalers that could help and a consultation with your pulmonologist may be a good option to help with finding the right balance of therapy.
A 34-year-old member asked:

How come breathing in during inspiration is not affected by bronchoconstriction (asthma/copd)?

1 doctor answer1 doctor weighed in
Dr. Brant Ward
Allergy and Immunology 14 years experience
Negative pressure: When you breathe in, your chest wall and diaphragm expand and create decreased pressure in your lungs. Because the bronchoconstriction is also inside your lungs, the negative pressure causes the airway to expand as well, and air flows in easily. When you breathe out, the chest wall and diaphragm relax, and pressure in the lungs increases. This snaps the airways closed again, like a valve.
A 46-year-old member asked:

Why is breathing in during inspiration not affected by bronchoconstriction (asthma or copd)?

1 doctor answer2 doctors weighed in
Dr. Dean Giannone
Internal Medicine 26 years experience
Pressure.: Long story...essentially, the pressure pushing upon the airways with expiration causes the airways to close upon themselves, causing air trapping which is one of the hallmarks of COPD and the other obstructive lung diseases.

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Last updated Jan 6, 2015


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