The term Continuous Positive Airway Pressure gives the first clue as to what a CPAP machine is and how it works.  Using a slight amount of pressure this machine forces or delivers a positive flow of oxygen to a person's nose and mouth throughout the night.  While the word "pressure" might seem a bit frightening, the pressure is adjusted for each patient's individual physical needs and is typically only enough to push the oxygen into his or her system; there's no need to think that this is going to over-inflate your lungs or cause damage in any way.  A CPAP machine operates by having a mask that resembles the oxygen masks you see in hospitals and doctor's offices connected by tubes to the body of the machine.  A patient slips this mask over his or her nose and mouth and this allows them to continue breathing throughout the night.

Some are a bit put off or hesitant to use the CPAP machine when it is first recommended to them because of how bulky the mask looks.  In truth, it might be a bit uncomfortable at first but many who use this machine report being very accustomed to it after only a few nights, and the relief they get from the use of the CPAP machine far outweighs the slight discomfort they feel.

It's important to realize that you should not use a CPAP machine unless you've been advised to do so by your doctor.  There are many places online that sell these machines without needing a doctor's note or prescription, but using an incorrect setting for its pressure can irritate your lungs at night.  You also don't want to rely on a CPAP machine if instead you should be concentrating on treating a certain medical condition or on losing weight or whatever else may be causing your breathing problems.