No matter what sleeping position you prefer, the best CPAP* mask will be the one that doesn’t compromise your therapy – and that means a mask that fits comfortably and has a secure seal.   
 
 But if you sleep on your side, you should be mindful about the mask you buy. That’s because your CPAP mask can dislodge when the side of your head rests on the pillow, which can compromise your mask seal, cause excessive leakage and result in airway blockages.
 
 Your mask should withstand the challenges of your sleeping style. But it should also be flexible and comfortable to wear. If your mask is overly firm, you may unwittingly remove it while you sleep – or give up on using it consistently enough for your therapy to be successful.  
 
 If you like to sleep on your side, you should look for masks that have secure but gentle cushions, comfortable surfaces, and soft and adjustable headgear. Avoid hard materials, such as metal buckles.