If you wake up in the morning feel abnormally tired and just downright awful, but later on in the day you start to feel much better, you might benefit from nocturnal oxygen therapy. Your doctor will ultimately help you determine if you need to use an oxygen concentrator while you are sleeping.
He or she will monitor your blood oxygen level while you are awake, and then while you are sleeping overnight, with the use of a pulse oximeter. If you have COPD that doesn't require you to use an oxygen concentrator during the day, it might be determined that you do need to use an oxygen concentrator while you are sleeping to keep your blood oxygen level where it should be.
Your breath rate changes when you fall asleep, and again when you fall into a deeper sleep. That's why you might not need it just while you are taking a little nap during the day. Your body wasn't given the time to fall into a deeper slumber.
When your breath rate changes like this when you enter the deeper stages of sleep, your lungs will have a harder time expelling the carbon dioxide and pulling in more oxygen present in the air. Because of this reason, the carbon dioxide is getting stuck in your blood stream and will be low on oxygen, which your whole body requires to function properly.
Getting enough oxygen to your brain is especially important, since your brain uses around 20% of how much oxygen you bring into your body. Nocturnal oxygen therapy patients usually experience a huge difference in the way they feel in the morning, after they start using it at night. It might take a few nights of using it every night to really feel the full difference. Patients have reported feeling much more energetic in the morning, and the head aches they usually have in the morning are gone.
If you only need to use oxygen therapy while you are sleeping, you won't really need to get a portable oxygen concentrator. You can if you'd like, as long as they will cover your oxygen dosage needs, but portable oxygen concentrators are usually more expensive than stationary oxygen concentrators.
It might not be necessary to have a portable model, since you won't be moving about while you are using it. However, if you are taking a long overnight flight, or a long road trip during which you will be sleeping in the vehicle, a portable oxygen concentrator will be necessary. You can't plug a stationary oxygen concentrator into a car DC outlet, or in any outlets on an airplane. In an airplane, you will definitely need an FAA approved portable model, as well as more than enough battery power to cover you during the flight.
Some great oxygen concentrators to use overnight, would be the Respirionics SimplyFlo, simply because of its great small size, as long as it covers your oxygen dosage needs. A great portable oxygen concentrator for overnight use would be SeQual Equinox, or the Lifechoice Activox.