Differences Between Chronic Bronchitis and Emphysema

Many people who have been diagnosed with the chronic obstructive pulmonary disease (COPD) wonder what the difference is between chronic bronchitis and emphysema.

Chronic bronchitis and emphysema are the two main subtypes of COPD—although, now just "COPD" is the preferred diagnostic term for people, regardless of their prior diagnosis of chronic bronchitis versus emphysema.

Sometimes, it's difficult to understand the differences between the two subtypes, especially because they usually coexist in the same person and both cause difficulty breathing.

One main difference between chronic bronchitis and emphysema is that chronic bronchitis refers to a health diagnosis—someone who has a chronic cough with mucous production every day for at least three months, for two years in a row. On the other hand, emphysema is a term that refers to the actual damage to the air sacs in the lung, called the alveoli. In other words, emphysema is a pathological term. 

Regardless, the diagnosis of chronic bronchitis and emphysema requires a thorough medical history, physical examination, and a test called spirometry, which measures how well your lungs are functioning. Spirometry can be performed in your doctor's office and is simple and easy, requiring you to breathe into a mouthpiece. 

Chronic bronchitis causes inflammation, or irritation, in the bronchioles of the lungs. The bronchioles connect the trachea, or windpipe, to the lungs and are used to carry air in and out of the lungs.

This irritation causes an increased amount of heavy mucus in the lungs that, over time, interferes with breathing. The body responds to this mucus by producing a cough in an attempt to clear the airways.

Because the mucus (also referred to as phlegm or sputum) is so abundant and thick, it's often difficult for a person with chronic bronchitis to expel it. This is why a person with chronic bronchitis experiences a cough every day for an extended period of time (three or more months, for two years in a row). This differentiates it from acute bronchitis.

Additionally, large amounts of thick mucus make the lungs a perfect habitat for bacteria to thrive. For this reason, bacterial lung infections among people who have chronic bronchitis are common and frequent.

The symptoms of chronic bronchitis include:

• coughing up clear or white mucus
• fatigue
• feeling short of breath
• chest discomfort or tightness

Chronic bronchitis is primarily caused by cigarette smoking, secondhand smoke, and air pollution.

Emphysema refers to the damage and destruction done to the walls of the alveoli, the tiny air spaces in the lungs where oxygen and carbon dioxide are exchanged during the breathing process. The alveoli provide oxygen to the bloodstream so when they are destroyed, it is difficult for the person with emphysema to breathe.

The symptoms of emphysema include:

• shortness of breath
• an ongoing feeling of not being able to get enough air
• long-term cough 
• wheezing
• long-term mucus production
• ongoing fatigue

Emphysema is primarily caused by smoking. 

A Word From Verywell

Even though COPD usually gets worse with time and cannot be cured, the good news is that there are therapies like inhalers, oxygen, and pulmonary rehabilitation that can help you. In addition, you can also be proactive in your care by not smoking and ensuring you are up to date on your flu and pneumonia vaccines.