How Is COPD Diagnosed?
Chronic obstructive pulmonary disease (COPD) is a preventable and treatable lung disease that’s characterized by limitation of airflow both into and out of the lungs. According to the Global Initiative for Obstructive Lung Disease, a COPD diagnosis should be considered in any patient who has shortness of breath, a persistent cough or mucus production and a history of exposure to risk factors including smoking, secondhand smoke, air pollution and workplace dust and chemicals. The following tests are often included when considering a COPD diagnosis:
A pulmonary function test (breathing test) known as spirometry is required to confirm a diagnosis of COPD. Persistent airflow limitation characteristic of COPD is substantiated when test results show a forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) of less than 0.70 after using a bronchodilator.
Additional Studies that Support a COPD Diagnosis
Although spirometry is needed to confirm a COPD diagnosis, additional studies are helpful in supporting that diagnosis and establishing disease severity. These include:
- Assessment of symptoms – If your health care provider suspects COPD, they will ask you about the nature and severity of your symptoms. Characteristic symptoms of COPD are persistent and progressively worsening shortness of breath, cough and mucus production. Wheezing and chest tightness may also be evident, especially in the presence of a COPD exacerbation (a period of time when COPD symptoms worsen). Fatigue, weight loss and anorexia (loss of appetite) are common problems in the more advanced stages of COPD.
- Review of your medical history – During your appointment with your provider, they will evaluate your medical history performing an assessment of your exposure to risk factors such as smoking, secondhand smoke, air pollution and/or workplace exposure to dust and chemicals. Your health care provider will also want to learn about your family history, the pattern of your symptom development and whether you have any other health conditions that may worsen COPD.
- Physical assessment – Although a physical assessment is rarely diagnostic in COPD, your health care provider will evaluate you physically, paying particular attention to any advanced symptoms of COPD, such as barrel chest, cyanosis and clubbing of the fingers.
- Chest X-ray – Although a chest X-ray is not useful in establishing a diagnosis of COPD, it is helpful when trying to rule out alternative diagnoses, such as certain heart diseases, lung cancer or pulmonary fibrosis.
- Additional pulmonary function tests – Other breathing tests help establish the severity of COPD and include body plethysmography and diffusion studies.
- Pulse oximetry and arterial blood gas studies – Both are used to evaluate the need for supplemental oxygen. If pulse oximetry is persistently less than 92%, an arterial blood gas study should be performed.
- Alpha–1-antitrypsin deficiency screening – Recommended for people who live in areas where there’s a high prevalence of alpha-1-antitrypsin deficiency (a rare, hereditary disorder that leads to emphysema) and for people who have COPD symptoms and are less than 45 years old.
- Exercise testing – Such as the 6-minute walk test is used to assess the degree of exercise impairment commonly seen in COPD. Exercise capacity is a strong predictor of disease prognosis, or how long a person will live after being diagnosed with COPD.
The Global Initiative for Obstructive Lung Disease. “Strategies for the Diagnosis, Management and Prevention of Chronic Obstructive Pulmonary Disease”. Updated January, 2015.
By Deborah Leader RN, BSN, PHN