Establishing the stage of your COPD helps your doctor decide on the best treatment plan to help you better manage your illness and your health. The GOLD Criteria has been modified in the last few years to more accurately classify people with COPD, according to Norman Edelman, MD, a core member of the program for public health at Stony Brook Medicine in Stony Brook, New York. “Originally, the GOLD Criteria were just based on the degree of airway obstruction that we found on breathing tests,” says Dr. Edelman. The criteria are based on results from a breathing test called spirometry, along with two other factors: severity of symptoms and how frequently an individual experiences acute exacerbations. Exacerbations are when someone’s COPD gets suddenly worse, according to Edelman. Based on the FEV1 score, your doctor can get an idea of how severe the airflow obstruction is, explains Diaz. “That’s the ‘O’ in COPD, and that’s how we quantitate the obstruction.” The results often correlate with the degree of symptoms. And Diaz notes that the FEV1 score can also have some prognostic implications.

GOLD 1 or Mild COPD: 80 percent of predicted FEV1 valueGOLD 2 or Moderate COPD: 50 to 79 percent predicted FEV1 valueGOLD 3 or Severe COPD: 30 to 49 percent predicted FEV1 valueGOLD 4 or Very severe COPD: Less than 30 percent of predicted FEV1 value

RELATED: Symptoms and Diagnosis of COPD

COPD Exacerbation or Flare Risk

The third factor that doctors consider when classifying a patient according to the GOLD Criteria is how frequently the patient experiences an acute exacerbation. COPD exacerbations can be mild, moderate, or severe.

Stage 1: Mild COPD

“During mild stage COPD, you may feel out of breath during light physical activity, like doing housework or walking up the stairs,” says Dr. Hatipoglu. “A hacking cough that produces mucus is also common,” he adds. “Diagnosing the disease early could help push smokers to stop and potentially dramatically improve their future.” Dr. Thomashow also notes that “having more mild disease does not necessarily mean there are no symptoms, [but] with available medications and rehab programs, we can often significantly improve these symptoms.” While smoking is the most common cause of COPD, long-term exposure to lung irritants — including secondhand smoke, air pollution, and industrial dust and fumes — can also be factors. RELATED: Causes and Risk Factors of COPD Catching and treating COPD early can help slow its progression, says Diaz. “If you’re not really experiencing symptoms, the most important reason to get diagnosed at an early stage is if you’re a smoker,” he says.

Stage 2: Moderate COPD

With moderate stage COPD, shortness of breath during daily activities is more evident, and you may also experience increased coughing and mucus production, says Hatipoglu. “If you’re suffering from moderate stage COPD, you could be a good candidate for a pulmonary rehabilitation program,” he says.

Stage 3: Severe COPD

“Once you reach severe stage COPD, your quality of life is significantly impacted,” says Hatipoglu. A person with severe COPD will begin to experience several symptoms, which can include the following:

Shortness of breath that has become worse or occurs more oftenMore coughing or wheezingChanges in thickness or amount of mucusExtreme fatigue or weaknessFeelings of confusion or forgetfulness

“Inhaled medications that will open up the airways and help a person breathe easier are often used, and for patients who get frequent exacerbations, we often prescribe inhaled corticosteroids,” says Edelman. When a person gets acute exacerbations, they are often prescribed antibiotics and several days of systemic steroids that come in the form of oral tablets, he adds.

Stage 4: Very Severe COPD

During end-stage or very severe COPD, almost everything you do causes shortness of breath and limits your mobility, says Hatipoglu. Breathing difficulties can even be life-threatening, and the lack of airflow coming into the lungs starts to affect the heart and circulatory system. “Oxygen therapy may be used in those with more severe disease,” says Thomashow. A portable oxygen tank can help improve your blood oxygen levels.

Quitting SmokingBronchodilatorsPulmonary RehabilitationOxygen Therapy Clinical Trials If you have severe COPD, you may be a candidate for a clinical trial (tests of new treatments). You can find potential clinical trials at ClinicalTrials.gov.

“People sometimes get the diagnosis of COPD and kind of ‘freak out,’” says Diaz. “They think it’s a death sentence, which is not the case. Not all of the COPD is the same; some can be very mild, and some can be more severe,” he says. “It’s possible to ‘hold steady’ or to delay progression of COPD by making lifestyle changes,” Diaz notes. “The most important thing to do is to stop smoking. If you’ve already stopped smoking, that can help slow the advancement of the disease.” If you or a loved one are diagnosed with COPD, remember there are treatment options. RELATED: Learn More About COPD Treatment and Prevention Additional reporting by Wyatt Myers.