Basics of Chronic Obstructive Pulmonary Disease

“Deep breathing is our nervous system’s love language.” – Dr. Lauren Mersy

Chronic Obstructive Pulmonary Disease (COPD) is a progressive lung disease that makes breathing increasingly difficult. According to the World Health Organization, it is the third leading cause of death worldwide. In this blog, we will unpack the fundamentals of COPD – what it is, signs and symptoms, various disease stages, as well as diagnostic tests available for detecting the disease.

What is COPD?

COPD is a condition caused by damage to the airways that blocks airflow and makes it hard to breathe. It manifests in one of two forms – emphysema and chronic bronchitis.

Emphysema

This is a chronic lung condition that involves damage to the alveoli. Now, what are alveoli? To understand alveoli, let us take a refresher on our respiratory system 101. As you may already know, when we breathe or inhale, air enters our lungs and gets filtered. This involves removing the bad stuff – carbon dioxide, a waste gas released from our working cells and tissues, and replacing it with the good stuff – oxygen. This process is assisted by the alveoli. They are the tiny air sacs in the lungs that act as filters so oxygen and carbon dioxide get exchanged.

In emphysema, the walls of these air sacs weaken and rupture. This is a problem because the many tiny sacs now combine to form larger sacs with reduced surface area. It’s like many air bubbles combining to form a large bubble. With less surface area, the amount of oxygen that can reach our bloodstream also becomes more limited. The physical signs or symptoms of emphysema may include shortness of breath, chronic coughing (especially in cases related to smoking), wheezing (a high-pitched whistling sound when breathing), and general fatigue. The fatigue experienced is typically the outcome of poor oxygen supply to the body tissues and organs, as well as the additional effort required to breathe.

Chronic Bronchitis

This is a condition that involves long-term inflammation of the bronchi. The bronchi are passageways for the inhaled air to pass to the two lungs. They end in tiny tubular sections called bronchioles which hold the alveoli. To better understand this, picture a tree. The trunk serves as one of the two bronchi (singular bronchus) and the roots that branch out from it are like the bronchioles. Likewise, similar to the way the roots absorb water and minerals from the soil, the alveoli absorb carbon dioxide from cells/tissues and exchange it with oxygen. Chronic bronchitis targets the ‘trunk’ or bronchi.

Irritants like cigarette smoke, air pollution, or industrial chemicals can damage the lining of the bronchi. The body responds to this irritation by initiating an inflammatory response. This response leads to many physiological changes. First, it increases the number of goblet cells. Goblet cells produce mucus. Mucus is a fancy word for snot! This ‘snot’ is not only there in your nose, but it is also there in the lining of your lungs. It traps dust and germs, preventing them from entering the body. Once this nasty stuff gets trapped, tiny hair-like structures called cilia work to move the mucus out of the lungs. In chronic bronchitis, goblet cells produce excessive mucus and cilia become less effective at clearing it out. This narrows our airways, making breathing difficult. Symptoms include coughing, shortness of breath, wheezing, and chest discomfort.

Diagnosis of COPD

COPD progresses in four stages. Doctors typically rely on the Gold Staging System or BODE Index to assess the stage of COPD.

The GOLD system looks at something called the forced excitatory volume. This is a measure of how much air a person can forcefully exhale. More specifically, the test assesses the volume of exhaled air in one second (called FEV1). A lower score indicates a poorer prognosis.

Likewise, the BODE Index is another tool for COPD diagnosis. It looks at four different factors:

• Body Mass Index (BMI): This measures a person’s weight about their height.
• Airflow Obstruction (FEV1): This is the same lung function test used in the GOLD Staging System.
• Dyspnea: This measures how breathless the person feels during daily activities.
• Exercise Capacity: This looks at how far the person can walk in 6 minutes.

Each of these four factors is scored from 0-3, with 3 being the most severe. The total BODE index score ranges from 0-10. A higher BODE index score indicates more severe COPD.

Stages of COPD

Stage 1

In the initial stage of COPD, lung function is quite okay, with the FEV1 typically around 80% or above the normal range. The median BODE index is around 0 (0-0). Many folks may not even be aware that they have the condition, as the symptoms can be quite subtle. Some may notice occasional coughing, the production of phlegm, or a slight difficulty breathing, especially during more strenuous activities.

Stage 2

In Stage 2 COPD, the FEV1 levels are between 50 and 80% of the normal range. The median BODE index is around 1 (1-4). Folks may experience more frequent coughing, increased mucus production, more breathing issues, and greater limitations with walking. To ease the symptoms, doctors typically prescribe bronchodilators or a pulmonary rehab program.

Bronchodilators are medications that help relax and widen the airways in the lungs, making it easier to breathe. Pulmonary rehabilitation programs, on the other hand, are comprehensive treatment plans. They typically include exercise training to improve cardiovascular fitness and muscle strength, education on managing the condition and lifestyle changes, nutritional counseling, and psychosocial support. The goal of these programs is to help patients with COPD become more physically active, reduce symptoms, and improve their ability to perform daily activities.

Stage 3  

Things take a more serious turn when we enter Stage 3 COPD. In this stage, the FEV1 falls somewhere between 30 to 50% of normal. The median BODE index is around 4 (3-6). Symptoms become even more difficult to manage, with more coughing, increased mucus production, and greater challenges breathing (even when performing daily activities). At this stage, doctors often prescribe corticosteroids.

Corticosteroids are medications that help reduce inflammation in the body and dampen the immune response.

Stage 4

Stage 4 is the worst – it’s called “end-stage COPD”. At this point, your FEV1 score becomes 30% or less than normal. The median BODE index is around 7 (5-8). A lot of people with stage 4 COPD have trouble getting enough oxygen, which leads to some concerning problems.

One key issue is hypoxia – that’s when your body’s tissues aren’t getting enough oxygen. Another is cyanosis – that’s when your skin starts turning blue. The blue color indicates inadequate oxygen levels in your blood. Doctors typically prescribe oxygen therapy. This involves getting pure or concentrated oxygen through a mask or tubes in your nose. It can make a big difference in relieving breathing troubles.

* COPD is a progressive lung disease that challenges those affected by making even simple breaths laborious. In future blogs, we will explore the risk factors of COPD along with effective lifestyle interventions.