Asthma is usually thought of as a separate lung disease, but it is sometimes confused with COPD, as they both have similar signs and symptoms, including coughing, wheezing, and trouble breathing. Patients with COPD can also show signs of right-sided heart failure, which can include increased fatigue and swelling in the legs, feet and ankles. Additionally, those with COPD usually feel symptoms between exacerbations, and the condition worsens with time, but asthmatic patients often feel normal between flares, and when properly treated, can have excellent control of their symptoms. Age of onset is also quite different for COPD vs asthma. COPD is usually diagnosed at age 45 or later, while asthma is most often diagnosed prior to that. Although smokers can develop asthma, too, almost everyone in the United States with COPD has a history of smoking.