According to studies, up to 90% of people with misdiagnosed COPD get COPD therapies on a regular basis, which might result in adverse outcomes and increase expenses to the healthcare system. Furthermore, other researches estimate that between 5% and 62 percent of COPD patients had been misdiagnosed. Other lung diseases that should be considered in the diagnosis of COPD include asthma, bronchitis, pneumonia, heart disease, and emphysema. COPD is often confused with asthma because they appear to involve many of the same symptoms. However, they differ in two important ways: asthma tends to be more likely to occur in young adults while COPD is more common as you get older. Also, asthma can be controlled by medications while COPD cannot be cured but it can be managed. Many people with COPD also have asthma or both disorders combined in what's called "airway hyperresponsiveness". This means that their airways are sensitive to certain factors such as cigarette smoke, pollen, dust mites, and viruses. When these triggers trigger an asthmatic response, there is increased mucus production, tightness of the muscles around the airways, swelling, and sometimes bleeding. In people who have both COPD and asthma, these responses are usually stronger to cigarettes smoke than in those with only one of these conditions. People with COPD may also have trouble breathing because of lung infections or severe allergies.