Auto CPAP machines or Continuous positive air pressure machines, are widely used to treat sleep apnea, a medical condition that causes temporary loss of breath during the night. CPAP machines are electronic devices that draw in outside air using an internal fan, humidify the air and pressurize it, and then deliver it to users via a connective hose and breathing face mask.CPAP pressurizes air to one constant level, depending on the user’s prescription to ensure you receive the optimum pressure levels for successful sleep therapy.