6 Answers

It forces air up your nose and makes you breathe. When you stop breathing it forces you too. Saves lives. It's for sleep apnea.

it helps the person to breath better duing sleep.It uses positve pressure oxgenation.Seep apnea has periods of less breathing. It is a machine with fitted mask. A person does what they call a sleep study to check 0-2 levels at the hospital.

Keeps your airways open during sleep,therefor keeping a steady flow of oxygen to your brain,,>>>>>>>><<<<<<<..  

It infuses moisture in the air that it pushes into the nasal passage, this meets the oxygen demands, and hydrates the structures, prevents apnea, and reduces snoring.  People who use it cannot believe how well they have restful sleep, and will not be without them. 

 lots of people with sleep apnea can breathe ok   on their side, but not on their back.

A CPAP (Continuous Positive Air Pressure) machine is a therapy device for persons who suffer from obstructed sleep apnea (OSA). If anybody reading this thinks they may have a sleep related problem, then they can open this link below and answer eight simple questions. It is universally known as the Epworth Sleepiness Scale and is used in many sleep labs as a prescreening tool for new patients:

http://sleepmedicine.com/files/Forms/epworth_sleepiness_scale.pdf 

For an overview of Obstructive sleep apnea I have inserted a Wiki link for those who may be interested:

https://en.wikipedia.org/wiki/Obstructive_sleep_apnea