COPD Versus Asthma
Some patients present with mixed COPD and asthma. There are several differences that help distinguish COPD from asthma. Asthma usually starts early in life, whereas COPD develops gradually and presents in mid-life. Asthma symptoms vary from day to day and can afflict the patient at night or in the early morning. Patients with COPD have difficulty breathing during exercise or exertion. Asthma often runs in the patient’s family whereas COPD tends to be a consequence of smoking rather than genetic inheritance. And finally, the symptoms of asthma can be reversed by administration of a bronchodilator, whereas the airflow limitation caused by COPD is largely irreversible.
Spirometry is the gold standard for diagnosing COPD. Spirometry measures the volume of air forcibly exhaled after the patient breathes as deeply as possible (forced vital capacity, FVC) and the volume of air exhaled during the first second (FEV1). The ratio of these values is then calculated (FEV1/FVC). The presence of an FEV1/FVC ratio <0.70 after administration of a bronchodilator (for example, albuterol) confirms a diagnosis of COPD.
Causes And Risk Factors Of COPD
Although smoking is the best-studied COPD risk factor, it is not the only one. Other risk factors include:
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