COPD Definition and Diagnosis

What is COPD?

COPD, or chronic obstructive pulmonary disease, is an umbrella term for two primary conditions: chronic bronchitis and emphysema.

Chronic bronchitis is a progressive lung disease that involves inflammation and thickening of the airways.

Emphysema causes the alveoli—the small air sacs in the lungs that provide oxygen to the bloodstream—to thin and become and less elastic.

Both conditions make it harder to breathe air in to get oxygen and even more difficult to push air out. This means carbon dioxide can’t be fully exhaled and it remains in the body as a toxin

What causes COPD?

OPD is the fourth leading cause of death, both globally and in the United States.

Over time, exposure to irritants that damage your lungs and airways can cause chronic obstructive pulmonary disease (COPD), which includes chronic bronchitis and emphysema. The main cause of COPD is smoking, but nonsmokers can get COPD too.


About 85 to 90 percent of all COPD  cases are caused by cigarette smoking. When a cigarette burns, it creates more than 7,000 chemicals, many of which are harmful. The toxins in cigarette smoke weaken your lungs' defence against infections, narrow air passages, cause swelling in air tubes and destroy air sacs—all contributing factors for COPD.

Your Environment

What you breathe every day at work, home and outside can play a role in developing COPD. Long-term exposure to air pollution, secondhand smoke and dust, fumes and chemicals (which are often work-related) can cause COPD.

Alpha-1 Deficiency

A small number of people have a rare form of COPD called alpha-1 deficiency-related emphysema. This form of COPD is caused by a genetic (inherited) condition that affects the body's ability to produce a protein (Alpha-1) that protects the lungs.

Symptoms of COPD

COPD symptoms can start out subtle and progress over time. People may confuse them with other conditions and not discuss their symptoms with their doctor.

Common symptoms of COPD include:

  • Fatigue
  • Shortness of breath (breathlessness)
  • Persistent cough
  • Frequent respiratory infections
  • Chest tightness and wheezing
  • Increased mucus production

How is COPD diagnosed?

If your doctor suspects you have COPD, they will review your symptoms and medical history before they run some tests to aid in your diagnosis.

  1. You may be asked to take a lung function test called spirometry.
  2. Spirometry can tell your doctor how well your lungs work by measuring how much air you can inhale, how much you can exhale and how quickly you can exhale.
  3. The spirometry results will help your doctor determine if you have COPD or another lung condition such as asthma.
  4. During a spirometry test, you will take a deep breath and blow as hard and as fast as you can into a tube. The tube connects to a machine that will assess how well your lungs work.
  5. Your doctor may also prescribe a chest X-ray or CT scan, which can help diagnose emphysema and may rule out other conditions such as heart failure, lung cancer or other lung diseases.

How is COPD treated?

There is no cure for COPD but there are lifestyle changes and treatments that can help you remain active, breathe easier and slow the progress of the disease. Learn more about the COPD symptoms, stages and treatment options. READ MORE