Cushion-style CPAP masks are good for people who sleep on their side or abdomen. Masks that cover the whole nose are good for people who move around a lot in their sleep. Nasal pillow CPAP masks are good for people who wear glasses or have claustrophobia issues, explains Mayo Clinic.
CPAP masks that cover the mouth and nose are prescribed to people who have a hard time breathing through their nose. Generally, doctors prescribe a nasal mask to apnea patients for one month before prescribing a full-face CPAP mask, states Mayo Clinic.
Continuous positive airway pressure, or CPAP, machines treat sleep apnea and snoring. CPAP masks deliver a steady stream of air that keeps breathing passages open. CPAP masks attach to a breathing hose and are held in place with headgear typically made of fabric, velcro and plastic clips, according to Dr. Brandon Peters for About.com.