Even those who don't have COPD or other chronic lung diseases, can have a hard time in high altitudes. Acute Mountain Sickness (AMS) can happen when you aren't used to a high altitude and you ascend too quickly for your body to adjust properly. AMS symptoms are difficulty sleeping, fatigue, headache, nausea or vomiting, unusual shortness of breath and a rapid pulse.
It's usually caught and treated in the mild stage, but severe AMS symptoms include chest tightness or congestion, a bluish tint to the skin, cough, confusion, inability to walk a straight line and coughing up blood. Needless to say, it can become life threatening if left untreated properly by medical personnel.
High altitudes can be serious business, as they can severely effect people with otherwise healthy lungs. If you're using an oxygen concentrator, this can give you a good buffer for dealing with the thinner air of higher altitudes. If you're talking about traveling up into the mountains, however, you will need to take some precautions.
All oxygen concentrators have a maximum operational altitude. This is the altitude at which your oxygen concentrator will still work just as well to deliver the same oxygen purity and volume that it did at lower altitudes. This maximum operational altitude is located in the specifications on the product page of the website for the oxygen concentrator, in the owners manual, or on the manufacturer's website.
Some oxygen concentrators will work just as well at a little over 8,000 feet, while others can go as high as 10,000, or 13,000 feet, and still deliver the same high oxygen purity. It's not wise to use an oxygen concentrator beyond its maximum operational altitude, for several reasons. It can cause damage to the concentrator, because it will start to work harder to produce the same amount of oxygen at the same purity. You also won't receive the amount of oxygen you need.
Besides staying under the maximum operational altitude, it's also important to go ascend slowly to allow yourself to grow accustomed to the higher altitudes. Take a few days before moving up, and then take the same amount of time when you're ready to come back down to where you were. It won't cause any kind of shock to your body, and your lungs, which are more sensitive and susceptible, will have time to adjust.
The most important things to do, is talk to you doctor before you go on any high altitude journeys. He or she will instruct you on safety, and let you know how much to increase your oxygen settings if you need to. He or she will also let you know if it's wise for you to do this at this point in time, and if you can physically handle it. You may also need to bring a pulse oximeter, so you can keep an eye on your blood oxygen level periodically. If you start to feel unwell, call a doctor and don't push yourself.