What is the worse and what is least worse
Ellen, you're right. COPD is an umbrella term that includes emphysema, chronic bronchitis and bronchiectasis. You're also right in that some people with COPD also have heart issues and a good doc will make sure to watch for those signs as well. Sometimes it's very difficult to determine whether breathing problems are COPD or heart related, so being on top of that is important.
I would strongly suggest www.copdfoundation.org as an excellent site for information about COPD as well as a place to keep track of the research being done in COPD.
You can't feel someone else's tooth ache. So I would say with some conviction that the worse type of COPD is the one you are suffering from.
The problems posed by emphysema versus chronic bronchitis versus bronchiectasis are all relative in many ways, and in some ways which you have at any given time makes absolutely no difference in how bad the disease is. Additionally, most of us have elements of both the two major ones and often we have elements of all three. Emphysema generally has to do with the ability of the alveoli in the lungs to exchangeCo2 for O2, and when that's diminished, it results in our being SOB. Chronic bronchitis is associated with thickening of the walls of the bronchial tubes and with excess mucous production which often contributes to exacerbations. Bronchiectasis is pooling of mucous in the bronchial tubes, often leading to many exacerbations. Both of the latter two involve a lot of coughing which leads to being SOB.
As stated, most of us have elements of at least two if not all three in our COPD. Very few people have only emphysema or chronic bronchitis or bronchiectasis, and if that's the case, the diagnosis should be one of those three and not COPD, assuming that a competent pulmonologist is making the diagnosis. So you take your pick