It's well known among the medical community that Chronic Obstructive Pulmonary Disease (COPD) can go for years undetected. In the early stages, COPD is very subtle. It's estimated that 2 out of 3 people with COPD have it, but don't know that they have it. The signs and symptoms don't become apparent until they have progressed to the moderate or even advanced stages of the disease. The signs of the early stage can be easily overlooked, or written off as something else.
It also doesn't help that many people don't have health insurance and don't qualify for medicaid or medicare because of income or age, so they put off going to the doctor for as long as they can, or they don't properly communicate how they feel to their doctor. Many people go through a denial and willfully-ignorant stage because they don't want to face the fact that something serious might be going on.
Despite these common and understandable road blocks, it's in your best interest to get tested for COPD after you've passed the age of 45, and for a number of other risk factors. The sooner COPD is caught, the better and more easily it can be treated and stopped from progressing, and the longer you will have to live. Your quality of life will improve greatly the sooner you acknowledge that something might be wrong.
The things that increase your risk of developing COPD are age (being 45 or older), family history, a personal history of asthma or other lung conditions, and a history of smoking or spending a lot of time in an environment with a poor air quality, such as working in a factory or living in a polluted city for many years. If you have one or more of these known risk factors, you should tell your health care provider so that you can schedule regular screenings for the disease.
COPD should be treated as a potentially dangerous disease, since it's one of the top 3 killer diseases in the United States, and the #4 killer worldwide. Aside from COPD being so dangerous, it's also surprisingly preventable, at least for the most part. It's estimated that between 80% to 90% of all cases of COPD are caused by smoking cigarettes. Cigarettes have been so popular over the past 5 decades and the habit is so hard to kick, it's really no wonder why COPD is killing so many people, even though it's known to be one of the most preventable diseases.
If you've been smoking for years, you should definitely get tested for COPD as soon as possible. What your doctor will do is order chest x-rays and blood work. The x-rays will show him or her if there are any damaged tissue in the lungs, and blood work will let them know if you have the right amount of oxygen and carbon dioxide in your blood.
Depending on your collective risk factors, your doctor will suggest that you come in for another screening in a few years. Quitting smoking will greatly reduce your likelihood of developing COPD, or at least prevent any future developments of the disease from becoming severe.