Stage III: Severe
During stage III of COPD, patients experience intensified symptoms, such as intensified shortness of breath, coughing, tiredness, and more frequent flare-ups.
Typically, you will also experience new signs of COPD progression, including getting colds more often, feeling tightness in your chest, swelling in your ankles and feet, having trouble catching your breath, and breathing issues when you exert yourself. Although your symptoms may have gotten worse, it’s important to stay active and pursue a healthy lifestyle to minimize COPD’s progression.
If you have not already completed a pulmonary rehabilitation program, ask your doctor for a referral. Pulmonary rehabilitation includes exercise training classes with expert therapists and is one of the most effective treatments available for alleviating your symptoms.
Stage IV: Very Severe
During stage IV of COPD, your quality of life will be lower, as your COPD begins to more greatly affect every activity. It will be difficult to breathe, even without exertion.
Chronic respiratory failure can also occur, in which not enough oxygen moves from your lungs into your blood or when your lungs don’t take enough carbon dioxide out of your blood.
Your doctor may prescribe supplemental oxygen to help with your breathing. At this point, other treatment options include surgery, having special valves implanted into your lungs or lung transplantation. [2]
References:
[1] https://www.mayoclinic.org/diseases-conditions/copd/symptoms-causes/syc-20353679
[2] https://perf2ndwind.org/the-four-stages-of-copd-explained/