Firstly the patient's history - a key to any diagnosis. The doctor will ask you questions about your symptoms, how long you have had them, if you have had asthma, how much you can do before you get breathless and if you have found anything that has helped you in the past. You will probably have told your doctor a similar story. You may well be a smoker or an ex-smoker.
Smoking is the main cause of chronic bronchitis and emphysema.
You may have been a lifelong asthma sufferer. Then the doctor will examine you. Before you even sit down, the doctor will have noticed if you are short of breath, coughing, wheezing or a bit blue around the edges from your breathing not being so good. He may also notice any nicotine stained fingers. COPD is not the only reason for breathlessness and so the doctor is likely to undertake a full physical examination, paying particular attention to your chest.