Understanding COPD: What It Is, How It Progresses, and What Options Are Available

Chronic obstructive pulmonary disease — more commonly known as COPD — is one of the most widespread lung conditions in the world. In the United States alone, it affects an estimated 16 million adults, and many more may have it without knowing. It's a leading cause of disability, hospitalisation, and death, and yet it remains widely misunderstood.

If you or someone you care about has been diagnosed with COPD, the volume of medical information out there can feel overwhelming. This guide is designed to break it down in plain language: what COPD actually is, what causes it, how it progresses, what current management options look like, and what clinical research is doing to move things forward.

What Is COPD?

COPD is a chronic lung condition that makes it progressively harder to breathe. It's not a single disease — it's an umbrella term that covers two closely related conditions: emphysema and chronic bronchitis. Most people with COPD have elements of both, though one may be more dominant.

Emphysema affects the air sacs (alveoli) deep in the lungs. In a healthy lung, these tiny sacs inflate and deflate with each breath, allowing oxygen to pass into the bloodstream and carbon dioxide to be expelled. In emphysema, the walls of these air sacs become damaged and lose their elasticity. They merge into larger, less efficient sacs, reducing the surface area available for gas exchange. The result is a feeling of breathlessness that gets worse over time — often described as trying to breathe through a straw.

Chronic bronchitis affects the airways (bronchial tubes) that carry air in and out of the lungs. These tubes become inflamed and produce excess mucus, narrowing the passage and making it harder to move air. The hallmark symptom is a persistent cough that produces mucus (sometimes called a "smoker's cough"), lasting at least three months a year for two consecutive years.

Emphysema and chronic bronchitis are sometimes referred to collectively as COPD, though the medical community increasingly uses COPD as the preferred diagnosis because most patients present with overlapping features of both.

What Causes COPD?

The single biggest cause of COPD is long-term cigarette smoking. According to most estimates, smoking accounts for around 85-90% of COPD cases. The longer someone smokes, and the more they smoke, the greater the risk.

That said, not everyone who smokes develops COPD, and not everyone with COPD has smoked. Other risk factors include:

Secondhand smoke exposure. Living or working with heavy smokers over a long period can cause enough cumulative lung damage to trigger COPD, even in people who have never smoked themselves.

Occupational exposure. Certain jobs involve long-term exposure to dust, chemical fumes, or vapours that can irritate and damage the lungs. Mining, construction, manufacturing, and agricultural work are among the higher-risk occupations.

Indoor air pollution. In some parts of the world, burning biomass fuels (wood, coal, animal dung) for cooking and heating in poorly ventilated spaces is a significant cause of COPD, particularly among women.

Genetics. A small percentage of COPD cases are linked to a hereditary condition called alpha-1 antitrypsin deficiency. Alpha-1 antitrypsin is a protein that helps protect the lungs. People with low levels of it are more susceptible to lung damage, and can develop COPD at a younger age — sometimes even without smoking.

Childhood respiratory infections. Severe lung infections in early childhood may affect lung development and increase the risk of COPD later in life.

Asthma. People with long-standing asthma, particularly if it's poorly controlled, may develop a condition that overlaps with COPD. This is sometimes called asthma-COPD overlap syndrome.

It's worth noting that COPD typically develops slowly. Most people are diagnosed in their 40s, 50s, or 60s, after years of gradual lung function decline. By the time symptoms become noticeable enough to prompt a doctor's visit, significant damage has usually already occurred.

Recognising the Symptoms

COPD symptoms tend to develop gradually, which is part of why the condition often goes undiagnosed for years. Many people dismiss early symptoms as normal ageing or being "out of shape." The most common symptoms include:

Shortness of breath. This is usually the symptom that eventually drives people to seek medical attention. It often starts with breathlessness during physical activity — climbing stairs, carrying shopping bags, walking uphill — and progresses over time until even routine tasks feel exhausting. In advanced COPD, breathlessness can occur at rest.

A persistent cough. Sometimes productive (bringing up mucus), sometimes dry. It may be worse in the morning or during cold weather. Many people attribute this to smoking itself rather than recognising it as a sign of chronic bronchitis.

Excess mucus production. Producing more phlegm or sputum than usual, particularly first thing in the morning, is a common early sign.

Wheezing. A whistling or squeaky sound when breathing, caused by narrowed or obstructed airways.

Chest tightness. A feeling of pressure or constriction in the chest, especially during physical exertion.

Frequent respiratory infections. People with COPD are more vulnerable to colds, flu, and pneumonia, and these infections tend to be more severe and take longer to recover from.

Fatigue. The effort required to breathe with damaged lungs consumes significant energy. Many people with COPD experience persistent tiredness that goes beyond normal fatigue.

If you're experiencing any combination of these symptoms — especially if you're over 40 and have a history of smoking or exposure to lung irritants — it's worth speaking with your doctor about testing for COPD.

How COPD Is Diagnosed

COPD is most commonly diagnosed using a simple breathing test called spirometry. You blow into a tube connected to a machine that measures two key things: how much air you can force out of your lungs in one second (FEV1), and the total amount of air you can exhale in a full breath (FVC). The ratio between these two numbers helps determine whether your airways are obstructed and how severely.

Your doctor may also use:

Chest X-ray or CT scan to look at the structure of your lungs and rule out other conditions.

Arterial blood gas analysis to measure oxygen and carbon dioxide levels in your blood.

Alpha-1 antitrypsin testing if you developed symptoms at a younger age or have a family history of COPD without a clear environmental cause.

COPD Stages and Progression

COPD is a progressive condition, meaning it tends to get worse over time. The rate of progression varies enormously from person to person and is influenced by factors like whether the person continues smoking, their overall health, and how well their symptoms are managed.

The most widely used classification system is the GOLD (Global Initiative for Chronic Obstructive Lung Disease) framework, which groups COPD into four stages based on lung function measured by spirometry:

GOLD Stage 1 — Mild. Lung function (FEV1) is 80% or more of the predicted normal value. Many people at this stage don't realise they have COPD. They may have a chronic cough and some mucus production, but breathlessness is minimal or absent.

GOLD Stage 2 — Moderate. FEV1 is between 50% and 79% of predicted. Shortness of breath becomes noticeable during physical activity, and coughing and mucus production may increase. This is often the stage at which people first seek medical attention.

GOLD Stage 3 — Severe. FEV1 is between 30% and 49% of predicted. Breathlessness is significant and limits daily activities. Exacerbations (flare-ups) become more frequent and more severe. Quality of life is noticeably reduced.

GOLD Stage 4 — Very Severe. FEV1 is below 30% of predicted. Breathing is severely impaired, and even basic activities like getting dressed or walking across a room can be exhausting. Exacerbations can be life-threatening and often require hospitalisation.

It's important to understand that GOLD staging is based on lung function numbers, but two people at the same stage can have very different day-to-day experiences. Doctors also assess symptom burden and exacerbation history when making management decisions.

COPD Exacerbations (Flare-Ups)

A COPD exacerbation is a period where symptoms suddenly get worse beyond normal day-to-day variation. Flare-ups can be triggered by respiratory infections (the most common cause), air pollution, cold weather, or sometimes without an obvious trigger.

During an exacerbation, you might experience increased breathlessness, more coughing, a change in the colour or amount of mucus, and a general feeling of being unwell. Mild exacerbations can sometimes be managed at home with changes to medication, but moderate to severe flare-ups may require emergency treatment or hospitalisation.

Exacerbations are more than just a bad day — they can cause permanent additional damage to the lungs, accelerating the progression of the disease. Reducing the frequency and severity of exacerbations is one of the primary goals of COPD management. This is also an active area of clinical research, with studies exploring new approaches to preventing and managing flare-ups.

Current Management Options

There is currently no cure for COPD. The damage to the lungs that has already occurred cannot be fully reversed. However, the right management plan can slow progression, reduce symptoms, improve quality of life, and lower the risk of exacerbations.

Quitting Smoking

For anyone with COPD who still smokes, quitting is the single most important thing they can do. It won't undo existing damage, but it significantly slows the rate of further decline. No medication or treatment can match the impact of smoking cessation on long-term outcomes.

Inhaled Medications

Most people with COPD will be prescribed one or more inhaled medications. These fall into a few categories:

Bronchodilators relax the muscles around the airways, making them wider and easier to breathe through. They come in short-acting forms (for quick relief) and long-acting forms (for daily maintenance). Long-acting bronchodilators include LABA (long-acting beta-agonists) and LAMA (long-acting muscarinic antagonists), which are often used in combination.

Inhaled corticosteroids (ICS) reduce inflammation in the airways. They're typically prescribed alongside long-acting bronchodilators for people who experience frequent exacerbations.

Combination inhalers deliver two or three medications in a single device — for example, a LABA/LAMA combination or a LABA/LAMA/ICS triple therapy.

Pulmonary Rehabilitation

Pulmonary rehabilitation is a structured programme that combines exercise training, breathing techniques, nutritional advice, and education about managing COPD. It's one of the most effective interventions available, and studies consistently show it improves exercise capacity, reduces breathlessness, and enhances quality of life. Despite this, it remains underutilised — many people with COPD are never referred or don't complete the programme.

Oxygen Therapy

For people whose blood oxygen levels drop below a certain threshold, supplemental oxygen may be prescribed. Long-term oxygen therapy (LTOT) is typically used for at least 15-16 hours per day and has been shown to improve survival in people with severe COPD and low blood oxygen.

Surgical and Interventional Options

In select cases, surgical options may be considered:

Lung volume reduction surgery (LVRS) removes damaged portions of the lung, allowing the remaining healthier tissue to work more efficiently.

Endobronchial valve placement is a less invasive alternative to LVRS. Small one-way valves are placed in the airways to redirect air away from damaged lung areas.

Lung transplantation is an option for a small number of people with very severe COPD who meet specific criteria.

Lifestyle Adjustments

Beyond medical treatment, day-to-day management of COPD involves staying physically active within your limits, maintaining a healthy diet, avoiding respiratory irritants, keeping up with flu and pneumonia vaccinations, and learning breathing techniques like pursed-lip breathing that can help manage breathlessness.

When Current Options Aren't Enough

Despite the range of treatments available, many people with COPD continue to experience significant symptoms and frequent exacerbations. Inhalers may help but don't fully control breathlessness. Pulmonary rehabilitation may improve fitness but doesn't stop the underlying disease from progressing. For a lot of people, there's a gap between what current treatments can do and what they need.

This is where clinical research becomes important. Research studies are constantly evaluating new medications, new combinations of existing medications, new delivery methods, and entirely new approaches to managing COPD. Without clinical research, the treatments available today — treatments that millions of people rely on — would not exist.

If you've been diagnosed with COPD and feel that your current management plan isn't giving you the results you'd hoped for, exploring a clinical research study may be worth considering. Studies are currently enrolling adults aged 40 and older with COPD at research sites across the United States.

See if you may qualify for a COPD clinical research study →

What Does Participating in a Clinical Research Study Involve?

For many people, the idea of joining a clinical research study feels unfamiliar or intimidating. Here's what it typically looks like:

Screening. You'll answer questions about your health, COPD history, and current medications to see if you meet the study's eligibility criteria. This can often be done online as a first step.

Informed consent. Before joining any study, the research team will explain exactly what the study involves — including the purpose, the procedures, potential risks, and your rights as a participant. You'll have time to ask questions and decide whether to proceed. Nothing happens without your consent.

Study visits. Depending on the study, you may visit a research site for scheduled appointments that could include physical exams, lung function tests, blood work, and check-ins with the research team. The frequency and duration of visits varies from study to study.

Study-related care at no cost. Visits, procedures, and any study medication are typically provided at no cost to participants. Compensation for time and travel may also be available, depending on the study.

Ongoing support. Throughout the study, you'll have regular contact with a medical research team that monitors your health and responds to any concerns.

Voluntary participation. You can withdraw from a study at any time, for any reason, without it affecting your regular medical care.

Clinical research studies are reviewed and approved by independent ethics committees before they begin, and they follow strict guidelines to protect participants.

Frequently Asked Questions About COPD

Is COPD the same as asthma?

No, though they share some symptoms. Asthma typically starts in childhood, involves reversible airway narrowing, and is driven by allergic or inflammatory triggers. COPD usually develops later in life, involves permanent structural changes to the lungs, and is most commonly caused by smoking. Some people have features of both, which is called asthma-COPD overlap.

Can COPD be cured?

As of now, there is no cure for COPD. Treatment focuses on managing symptoms, slowing progression, and reducing flare-ups. However, clinical research continues to explore new approaches — and what's considered the standard of care today may improve as new findings emerge.

Is emphysema the same as COPD?

Emphysema is one of the two main conditions that fall under the COPD umbrella (the other being chronic bronchitis). So emphysema is a type of COPD, but COPD can also include chronic bronchitis or a combination of both.

What does chronic bronchitis mean?

Chronic bronchitis is defined as a persistent cough that produces mucus for at least three months a year, for at least two consecutive years, when other causes have been ruled out. It's caused by inflammation and excess mucus production in the bronchial tubes.

Can you get COPD without smoking?

Yes. While smoking is the leading cause, COPD can also result from long-term exposure to secondhand smoke, occupational dust and chemicals, indoor air pollution, or genetic factors like alpha-1 antitrypsin deficiency. An estimated 10-20% of COPD cases occur in people who have never smoked.

What is a COPD exacerbation?

An exacerbation (also called a flare-up) is a period of worsening symptoms that goes beyond normal day-to-day variation. Common triggers include respiratory infections, air pollution, and cold weather. Exacerbations can range from mild (manageable at home) to severe (requiring hospitalisation).

What is the GOLD classification?

GOLD stands for the Global Initiative for Chronic Obstructive Lung Disease. It's an international framework that classifies COPD severity into four stages based on lung function tests, along with assessments of symptom burden and exacerbation history. It's widely used by doctors to guide treatment decisions.

Taking the Next Step

Living with COPD means adapting to a condition that changes over time. The right management plan — developed with your doctor — can make a meaningful difference in how you feel day to day and how quickly the condition progresses.

For those who feel their current approach isn't providing enough relief, clinical research offers a way to access new approaches while contributing to the broader understanding of COPD. Studies are enrolling now for adults aged 40 and older.

Check your eligibility for a COPD clinical research study →

This article is for informational purposes only and is not intended as medical advice. Always consult your doctor before making decisions about your health or treatment plan.