How Chronic Obstructive Pulmonary Disease (COPD) Is Diagnosed

According to the Global Initiative for Chronic Obstructive Lung Disease (GOLD), a diagnosis of chronic obstructive pulmonary disease (COPD) should be considered in any patient who has shortness of breath, a long-term cough or sputum production, and/or a history of COPD risk factors, such as smoking, exposure to lung irritants like chemicals, and others. However, diagnosing COPD can be complicated since it has similar symptoms to other illnesses and may manifest itself differently in each individual.

COPD diagnosis
© Verywell, 2018

History and Physical

Your assessment will start with a detailed look at your history. This should include a review of the following:

  • Your current and past exposure to risk factors such as smoking, secondhand smokeair pollution, and/or occupational exposure to dust, gases, and chemicals
  • Your medical history, especially as it pertains to current respiratory disorders like asthma, allergies, sinusitis, and/or respiratory illnesses during your childhood
  • Prior hospitalizations, especially if they were associated with respiratory illnesses
  • If anyone in your family has ever had COPD or any other chronic lung disease
  • If you have other existing medical conditions, such as heart disease or osteoporosis, which may further impact a diagnosis of COPD
  • The pattern of your symptom development, including when your symptoms started and how long you waited before seeking medical attention
  • The impact of your symptoms in your everyday life (e.g. if symptoms have caused you to miss work, limit your regular activities, or feel depressed or anxious)

Your doctor should also perform a thorough physical examination that may include:

  • Taking your temperature, pulse, breaths per minute, pulse, and blood pressure
  • Listening to your heart and lungs with a stethoscope
  • Examining your ears, nose, eyes, and throat for signs of infection
  • Examining your fingers for signs of cyanosis
  • Assessing for signs of swelling in your legs, ankles, feet, or other parts of your body
  • Evaluating the veins in your neck to assess for complications of COPD

Labs and Tests

In addition to the above, your doctor will also need to perform some tests if he or she suspects COPD.

Spirometry

spirometry test is required to make a clinical diagnosis of COPD and is the primary tool for evaluating the severity of the condition. This test looks specifically at four key measures of lung function, including:

Together, these four measures not only tell how much damage has been done to your lungs but the ways in which you can improve your long-term outcomes should you have COPD. Persistent airflow limitation, or COPD, is confirmed when test results show an FEV1/FVC of less than 0.70 after you use a bronchodilator.

Additional Pulmonary Functions Tests (PFTs)

In addition to spirometry, there are two other pulmonary function tests that are important when evaluating lung function in COPD: lung diffusion tests and body plethysmography. These tests measure how much carbon monoxide your lungs are able to process and the volume of air in your lungs at different stages of breathing, respectively, specifying how severe your COPD is.

Complete Blood Count (CBC)

Though blood tests can't diagnose COPD, a complete blood count (CBC) will alert your doctor if you have an infection, as well as show, among other things, how much hemoglobin is present in your blood. Hemoglobin is the iron-containing pigment in your blood that carries the oxygen from your lungs to the rest of your body.

Pulse Oximetry

Pulse oximetry is a noninvasive method of measuring how well your tissues are being supplied with oxygen. A probe or sensor used to get this reading is normally attached to your finger, forehead, earlobe, or the bridge of your nose. Pulse oximetry can be continuous or intermittent, and a measurement of 95 percent to 100 percent is considered normal. If you're under 92 percent, your doctor may want to do an arterial blood gas (ABG) assessment. Along with ABGs, measuring your oxygen saturation level by way of pulse oximetry helps your doctor assess your need for oxygen therapy.

Arterial Blood Gases

In COPD, the amount of air that you breathe into and out of your lungs is impaired. Arterial blood gases measure the oxygen and carbon dioxide levels in your blood and determine your body's pH and sodium bicarbonate levels. ABGs are important in forming a diagnosis of COPD as well as in determining the need for and adjusting the flow rate of any needed oxygen therapy.

Alpha-1-Antitrypsin Deficiency Screening

If you live in an area where there is a high prevalence of alpha-1-antitrypsin (AAT) deficiency, the World Health Organization (WHO) recommends that you be tested for this disorder with a simple blood test. In fact, WHO recommends that anyone who has been diagnosed with COPD should be screened for AAT deficiency once.

AAT deficiency is a genetic condition that can lead to COPD. Being diagnosed at a relatively young age (under 45 years old) should also alert doctors to the possibility that AAT deficiency is the underlying cause of your COPD. Treatment for COPD that is caused by AAT deficiency is different than the standard treatment and includes augmentation therapy.

Imaging

Imaging tests may be added to rule out or diagnose COPD.

Chest X-ray

A chest x-ray alone does not establish a diagnosis of COPD. Your doctor may order one initially, however, to rule out other reasons for your symptoms or to confirm the presence of an existing comorbid condition. A chest X-ray may also be used periodically throughout your treatment to monitor your progress.

Computerized Tomography (CT) Scan

Although a CT is not routinely recommended when making a diagnosis of COPD, your doctor may order one when it’s indicated. For instance, you may have a CT scan if you have an infection that's not resolving; your symptoms have changed; your doctor suspects you may have lung cancer; or if you're being considered for surgery.

While a chest X-ray shows larger areas of density in the lungs, a CT scan is more definitive, showing fine details that a chest X-ray does not. Sometimes, prior to a CT scan, a material called contrast is injected into your vein. This allows your doctor to see the abnormalities in your lungs more clearly.

Differential Diagnoses

While various respiratory tests, such as spirometry, can confirm the symptoms of the disease, they alone cannot confirm the diagnosis. For this, a doctor needs to make what is called a differential diagnosis, wherein all other causes of the illness have been methodically excluded. Only when the process is complete can a COPD diagnosis be considered definitive.

A differential diagnosis is vital to confirming COPD because it remains such an elusive illness. While COPD is predominantly associated with cigarette smoking, not all smokers have COPD and not everyone with COPD is a smoker.

Moreover, the symptoms and expression of the disease are highly variable. For example, a person for whom spirometry tests are inconclusive can often have severe COPD symptoms. Alternately, someone with marked impairment can often manage with few, if any, symptoms.

This variability requires doctors to look at the disease differently. And, because we don't yet fully understand what triggers COPD, doctors need the safety net of a differential diagnosis to ensure the right diagnosis is made.

This is especially true for older people in whom heart and lung disease can cause airway restriction. By turning over every proverbial stone, doctors can often find the actual (rather than presumed) cause of the breathing disorder, which may be treatable.

In the course of a differential diagnosis, some of the more common investigations would include asthma, congestive heart failure, bronchiectasis, tuberculosis, and obliterative bronchiolitis. Depending on the health and history of the individual, other causes may also be explored.

Asthma

One of the most common differential diagnoses of COPD is asthma. In many cases, the two conditions are virtually impossible to tell apart, which can make management difficult since the treatment courses are extremely different. The characteristic features of asthma include:

  • Generally begins early in life (COPD happens later)
  • Symptoms that vary almost daily, often disappearing between attacks
  • Familial history of asthma
  • Allergies, rhinitis, or eczema
  • Airflow limitation that is essentially reversible, unlike COPD

Congestive Heart Failure

Congestive heart failure (CHF) occurs when your heart is unable to pump enough blood through the body to keep everything functioning normally. This causes the backup of fluids in your lungs and other parts of your body. Symptoms of CHF include a cough, weakness, fatigue, and shortness of breath with activity. Other characteristics of CHF include:

  • Fine crackles heard with a stethoscope
  • Excessive fluid and dilation of the heart muscle seen on chest X-ray
  • Volume restriction detected with pulmonary function tests (as opposed to airflow restriction seen in COPD)

Bronchiectasis

Bronchiectasis is an obstructive lung disorder that can either be congenital (present at birth) or caused by early childhood diseases such as pneumonia, measles, influenza, or tuberculosis. Bronchiectasis can exist alone or co-occur alongside COPD. The characteristics of bronchiectasis include:

  • Producing large amounts of sputum
  • Recurrent bouts of bacterial lung infection
  • Coarse crackles heard via stethoscope
  • Chest X-ray shows dilated bronchial tubes and thickened bronchial walls
  • Clubbing of the fingers

Tuberculosis

Tuberculosis (TB) is a highly contagious infection caused by the microorganism Mycobacterium tuberculosis. While TB normally affects the lungs, it can spread to other parts of the body as well, including the brain, kidneys, bones, and lymph nodes.

Symptoms of TB include weight loss, fatigue, persistent cough, breathing difficulty, chest pain, and thick or bloody sputum. Other characteristics of TB include:

  • Disease onset at any age
  • Air spaces filled with fluid seen on chest X-ray
  • Presence of M. tuberculosis detected by blood or sputum tests

Your doctor will also look to confirm if TB has been identified in your community or consider any recent outbreaks.

Obliterative Bronchiolitis

Obliterative bronchiolitis is a rare form of bronchiolitis that can be life-threatening. It occurs when the small air passages of the lungs, known as the bronchioles, become inflamed and scarred, causing them to narrow or close. Other characteristics of obliterative bronchiolitis include:

  • Generally occurs at a younger age in non-smokers
  • Possible history of rheumatoid arthritis or exposure to toxic fumes
  • CT scan shows areas of hypodensity where the lung tissue has thinned.
  • Airway obstruction, as measured by the FEV1, may be as low as 16 percent.

Grades

If your doctor confirms that you have COPD, he or she will then determine your stage by referring to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) grading system, which divides disease progression into four distinct stages that are determined by a spirometry test.

These stages, which define the progressive nature of the illness, can help you know what to expect at that moment in your disease course, though your stage doesn't decide how well you will do with treatment. 

Grade 1: Mild COPD

With grade 1 COPD, you have some airflow limitation, but you'll likely be unaware of it. In many cases, there will either be no symptoms of the disease or the symptoms will be so minor they are attributed to other causes. If present, symptoms can include a persistent cough with the visible production of sputum (a mixture of saliva and mucus). Because of the low-grade symptoms, people at this stage will rarely seek treatment.

Grade 2: Moderate COPD

With grade 2 COPD, your airflow limitation begins to worsen, and the symptoms of COPD become more apparent. These symptoms can include a persistent cough, an increased production of sputum, and a shortness of breath upon minor exertion. This is typically the stage when most people seek treatment.

Grade 3: Severe COPD

With grade 3 COPD, the restriction and/or obstruction of your airway passages is evident. You will experience a worsening of acute symptoms, known as COPD exacerbation, as well as an increased frequency and severity of coughing. Not only will you have less tolerance for physical activity, there will be greater fatigue and chest discomfort.

Grade 4: Very Severe COPD

With grade 4 COPD, your quality of life will be profoundly impaired with symptoms ranging from serious to life-threatening. The risk of respiratory failure is high in grade 4 disease and may lead to complications with your heart, including a potentially fatal disorder called cor pulmonale (failure of the right side of your heart).

Groups

GOLD also came out with guidelines to further categorize patients with COPD into groups labeled A, B, C, or D. These groups are defined by how severe COPD-related problems are, such as fatigue; shortness of breath; how much symptoms interfere with your daily life; and how many exacerbations you've had in the last year. Utilizing both grades and groups can help your doctor come up with the best treatment plan for your individual needs.

Group A

You've had no exacerbations or just one small exacerbation that didn't require hospitalization in the past year. You have mild to moderate shortness of breath, fatigue, and other symptoms.

Group B

You've had no or only one minor exacerbation that didn't require hospitalization in the past year. You have more severe shortness of breath, fatigue, and other symptoms.

Group C

You've had one exacerbation that required hospitalization or two or more exacerbations that may or may not have required hospitalization in the past year. Your COPD symptoms are mild to moderate.

Group D

You've had one exacerbation of hospitalization or two or more exacerbations with or without hospitalization in the past year. Your COPD symptoms are more severe.

Was this page helpful?
Article Sources