Chronic obstructive pulmonary disease, also called COPD, causes breathing problems that get progressively worse over time, according to the National Heart Lung and Blood Institute. Smoking is the leading cause of COPD. Air pollution, chemical fumes and dust may also contribute to the lung disease. The two main conditions of COPD include emphysema and chronic bronchitis. Emphysema causes damage to lung tissues. Chronic bronchitis inflames and irritates the lining of the airways, causing the lining to thicken, making it difficult to breathe.
Early Condition
During stage I of COPD, patients may have shortness of breath, with or without coughing and/or clear mucus, according to the COPD International website. Abnormal lung function usually goes unrecognized at this point. Increased bouts of coughing may signal the beginning of COPD. People may blame the coughing on other causes, such as a virus or smoking, which they may consider a mild concern at the time. However, smoking is the major cause of COPD.
Moderate Stage
Moderate to severe shortness of breath may occur from exertion during stage II. People may develop unusual breathing patterns, such as breathing out through pursed lips. Patients often seek medical attention at this time because of chronic respiratory symptoms or worsening conditions. A mild cough may occur, often in the morning. The cough may produce yellow or green sputum and develops around age 45, according to the Merck Manuals Online Medical Library. For some people, persistent cough and sputum production may increase when shortness of breath results from a lung infection.
Severe Phase
In stage III, severe shortness of breath begins to break down the quality of life from illness, fatigue or reduced ability to perform basic physical activities. People who do not quit smoking by age 65 become particularly affected. Pneumonia and other lung infections may occur more often. Chronic bronchitis or emphysema may develop. Air pollution, common allergens and viral or bacterial infections can easily cause COPD flare-ups that worsen the condition. Severe weight loss, difficulty eating because of shortness of breath, morning headaches from breathing problems and swelling of the legs may occur. People with COPD may begin coughing up blood during this stage.
Final Period
During stage IV, the quality of life has diminished because of severe shortness of breath that may bring about life-threatening conditions, including acute respiratory failure. Areas of the lungs may rupture, causing sudden pain or breathing difficulties that need immediate medical care, Merck Manuals notes. Doctors may remove air that has leaked into the pleural space, a cavity between the lungs and the chest wall, from ruptures. Symptoms worsen and sputum color changes to yellow or green. Fever and body aches may develop. Shortness of breath can occur even during rest, requiring hospitalization and oxygen therapy. COPD patients may also suffer from severe anxiety, sweating and confusion. Breathing abilities worsen until complications result in death.
