How smoking causes pulmonary emphysema

Written by: Top Doctors®
Edited by: Top Doctors®


What is pulmonary emphysema?


Pulmonary emphysema is a progressive long-term disease of the lungs that causes shortness of breath. The disease is most frequently caused by smoking, and causes the destruction of lung tissue around smaller airways (bronchioles).


A healthy bronchiole will hold its shape when a person exhales, but in lungs affected by emphysema, this doesn’t happen and the bronchioles become inefficient at transferring oxygen into the blood and taking carbon dioxide out.


The affects of smoking on the lungs


There are two main components in the structure of the lungs:


  • The bronchi, which branch successively from the trachea in an almost tree-like formation, are tiny in diameter - up to 1 mm - and are the main passageway for air into the lungs.
  • The alveoli, which are millions of spherical microscopic units (air sacs) with very thin walls - much thinner than the finest paper - and whose function is to enable the exchange of oxygen and carbon dioxide in the bloodstream.

The components of tobacco, either directly by toxic effect or by inflammation, cause the walls of the alveoli to pop like soap bubbles.

In emphysema, when the alveoli are broken, the filter surface of the lungs becomes smaller, so the oxygen transport is less efficient.


What are the symptoms of pulmonary emphysema?


The main symptom of emphysema is shortness of breath, especially when walking or climbing stairs. Many smokers will have had cough for years, but may have disregarded those symptoms.


Diagnosis of pulmonary emphysema


Emphysema is diagnosed by your consultant pulmonologist in the following ways:

  • Laboratory tests to measure respiratory function: spirometry, bronchodilator test, plethysmography and diffusing capacity of the lungs for carbon monoxide (DLCO). The first sign is a decrease in the DLCO.
  • Chest CT scan: Thanks to the three-dimensional reconstructions produced by the CT scan we know that emphysema usually starts in the upper regions of the lungs and then progresses downwards. The images imitate a run in a stocking or the breakage of a net.


What it means to be diagnosed with pulmonary emphysema


In the early stages, Emphysema is more of a warning than terrible news, but if the patient continues to smoke the bronchial obstruction will advance, causing a decrease in oxygen in the blood and ultimately respiratory failure. The greater amount of tobacco accumulated, the greater the emphysema.

Sometimes, even if a smoker has quit, if there is a chronic damage to the lungs, the disease does not stop and even progresses.

Another symptom of emphysema is that the retained air can deform the chest (creating a barrel shape) and can cause issues such as not allowing them to go underwater in a swimming pool. The expanded chest acts as a floatation device.


Treatment for pulmonary emphysema


Emphysema is irreversible and, therefore, the sooner the patient quits smoking the better. The obstruction can be relieved with the use of bronchodilators and anti-inflammatories, and antibiotics. Respiratory failure is treated with oxygen.


By Topdoctors
Pulmonology & respiratory medicine

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