There are few different causes for this, some of which are chronic lung diseases like emphysema, while are reasons might be a serious injury to your lungs that caused long-term damage. You might know someone who also has COPD, who does not need OXYGEN THERAPY.
Chronic Obstructive Pulmonary Disease comes in different levels of severity, which also depend on the patient's cooperation in his own health. If he has been smoking – the main cause of COPD – for many years and has continued to smoke long after his diagnosis, his condition will worsen and he will likely need to use oxygen therapy. Studies show that quitting smoking actually significantly slows or even stops the progression of the disease.
No matter the cause of your continuous low blood oxygen level, your lungs cannot absorb enough oxygen into your bloodstream because of damage to the alveoli, which are the tiny gateways between the lungs and your blood. The alveoli absorb oxygen into your blood and carbon dioxide from your blood into your lungs, so you can breathe it out.
Why is oxygen so important?
Every cell in your body needs oxygen to survive, just as all animals need certain amounts of oxygen to live. Imagine a fish in a fish tank with a faulty air pump. If the air pump stops working, the fish will quickly get sick and die. If your lungs can't inspire enough oxygen, you're like the fish with the air pump that has stopped working. Eventually, your body will give out, your brain and heart suffering the most damage.
The air around you only consists of about 21% oxygen, the rest is nitrogen and other various gases, depending on where you are at the time. You might find that you feel better after spending some time out in nature, surrounded by trees and lush greenery. This is because plants exhale oxygen. The more you are around them, the more oxygen you're getting.
How does oxygen therapy work?
You would be using either an OXYGEN MACHINE with an oxygen tank, or an oxygen concentrator. These machines are set so that you are getting predetermined amounts of pure oxygen as you inhale, through a face or a nasal cannula. Because the air around you is only 21% oxygen, the oxygen machine gives you larger amounts of pure oxygen, so your body is able to absorb more.
If your blood oxygen level is always low, even when you are at rest, your doctor will likely find it necessary for you to take constant oxygen. Depending on the details of your condition, he may only have you use it at night when you sleep, or while you are being active.