A Guide to the Four COPD StagesJuly 19, 2019
Chronic obstructive pulmonary disease (COPD) is a progressive lung disease, meaning it worsens over time. It results in restricted airflow into the lungs, which makes breathing difficult. COPD can have numerous causes, including smoking and long-term exposure to air pollutants, as well as a rare genetic disorder. Patients generally go through four stages of the disease, from least to most severe. Lung function tests are the most common method to determine these stages.
- Understanding the Tests
Doctors take two measurements during a breathing test to judge how far a patient's COPD has progressed. The measurements are taken using a device called a spirometer.
- Forced vital capacity (FVC) measures how much air a patient can breathe out quickly and forcefully after a deep breath.
- Forced expiratory volume (FEV1) measures how much air is blown out in the first second of the test.
- What Test Results Mean
By comparing the FEV1 measurement to the FVC measurement, a doctor can determine the percentage of the total lung capacity a patient can breathe out in one second. That ratio can help diagnose the specific type of COPD involved - emphysema, chronic bronchitis or both. The FEV1 score is compared to average figures from healthy individuals to help determine the COPD stage, as follows:
- Stage 1 (Mild COPD) is defined with FEV1 results of 80% or higher than those of healthy individuals. Patients in Stage 1 might experience coughing or increased mucus but might not know they have COPD. At this stage, your doctor might suggest breathing exercises and lifestyle changes, like quitting smoking if you’re a smoker.
- Stage 2 (Moderate COPD) is defined with FEV1 results between 50% and 80% of those of healthy individuals. Symptoms include shortness of breath, wheezing and excess mucus. Your doctor might prescribe bronchodilator medication to help open your airways.
- Stage 3 (Severe COPD)is defined with FEV1 results between 30% and 50% of those of healthy individuals. COPD at this stage can have a big impact on quality of life. Symptoms can make it difficult to perform daily tasks. Your doctor might prescribe corticosteroids to help reduce inflammation, along with a combination inhalers and other medications.
- Stage 4 (Very severe COPD) is defined with FEV1 results below 30%. This is also called end-stage COPD. At this point, flare-ups and breathing problems can become life-threatening. Low blood oxygen can lead to several serious health conditions, including hypoxia, hypoxemia and cyanosis. Your doctor might prescribe oxygen therapy to lessen such risks.
- Additional Tests
To help determine possible treatments, physicians also want to know how a person's disease might be affecting their daily life. This is accomplished through a number of additional tests that determine a patient's BODE Index, which includes:
- Body mass index (FVC), which compares weight to height. This can help determine any special nutritional needs.
- Obstruction of airflow, using FEV1 and FVC test results.
- Dyspnea, which means breathing difficulty. This helps doctors understand how shortness of breath could be affecting quality of life.
- Exercise capacity, measured in a 6-minute walking test. This shows how much exercise you can tolerate before symptoms begin.