Diagnosing Chronic Obstructive Pulmonary Disease

NYU Langone specialists are experienced in diagnosing chronic obstructive pulmonary disease, also known as COPD. This lung condition causes breathing difficulties, which worsen over time.

There are two main types of COPD: chronic bronchitis and emphysema. In chronic bronchitis, the lining of a person’s airways becomes inflamed and produces thick mucus. In emphysema, the lungs’ air sacs are damaged, depriving your body of oxygen.

Most people with COPD have both of these conditions, and the most common cause is smoking. COPD tends to affect more men than women, since men are more likely to smoke. However, women are more susceptible to the lung-damaging effects of smoking.

Less common causes include long-term exposure to lung irritants, such as dust, smoke and chemical fumes. Rarely, people with emphysema have a genetic condition called alpha-1-antitrypsin, which causes progressive lung damage.

Signs and Symptoms

The lungs contain bronchial tubes, called bronchi, which branch into thousands of smaller tubes called bronchioles. At the end of these tubes are tiny, elastic air sacs called alveoli. When you inhale, air enters the bronchial tubes, and each sac fills with air. When you exhale, the sacs deflate.

Each of these air sacs is surrounded by tiny blood vessels called capillaries. They are covered by a network of arteries and veins. When air reaches the sacs, oxygen passes into the blood and can travel throughout the body via the blood vessels.

In people with COPD, airflow is restricted. In emphysema, the air sacs collapse, interfering with oxygen and airflow out of the lungs. In chronic bronchitis, inflammation causes the airways to thicken, produce mucus, and become narrow, which interferes with breathing.

Symptoms include frequent shortness of breath, wheezing, and chronic cough, with or without mucus. Since breathing is difficult, many people have trouble participating in their usual activities, such as walking and exercising. Sometimes people with COPD experience flare-ups, in which symptoms worsen and breathing is so difficult it may require immediate emergency treatment.

Although most people with COPD develop symptoms around age 40 or older, the age of onset depends on your smoking history—when you started, how long you smoked, and how many cigarettes you smoked. In general, the longer a person smokes, the greater the risk of COPD.

Over time, untreated COPD can cause respiratory infections, pulmonary hypertension—a type of high blood pressure that affects arteries in the lungs and heart—and, in severe instances, respiratory failure and heart failure due to a lack of oxygen. COPD can also affect your quality of life, limiting physical activity and preventing you from doing the things you enjoy.

Diagnostic Tests

To diagnose COPD, your doctor takes a medical history, assesses your breathing, and orders imaging tests.

Medical History

Your doctor asks whether you’ve smoked or been exposed to lung irritants. Both smoking and chronic exposure to lung irritants, such as dust and chemical fumes, can increase your risk of developing the condition.

Pulmonary Function Test

Doctors use a group of tests known as pulmonary function tests to assess lung function. These tests measure the amount of air your lungs can hold, how quickly you can inhale and exhale air, and the amount of oxygen in the blood.

People with COPD tend to have trouble exhaling, so your doctor may order a spirometry test, which measures how much and how quickly you can exhale. It’s the most commonly used pulmonary function test for COPD.

Chest X-ray

A chest X-ray uses electromagnetic radiation to produce an image of the structures in your chest, such as your heart and lungs. An X-ray can detect abnormalities in your lungs that may indicate COPD. It can also be used to rule out other pulmonary conditions.

CT Scan

A CT scan uses X-rays and a computer to create three-dimensional, cross-sectional images of the body. It can reveal the airway inflammation commonly found in chronic bronchitis and the destruction of the lung tissue that is typical of emphysema.