Patient can have difficulty tolerating CPAP for many different reasons some of which are discussed below. In the case of claustrophobia, specific desensitization steps are recommended.
In general, CPAP tends to dry out the air and therefore extra humidification is usually required. Most commonly a pass-over humidifier is used, although the amount of humidification achieved by this means is less than that obtained by using a heated humidifier.
Occasionally too much humidification can irritate the nasal mucosa and sinuses, and the temperature of heated humidification may be too much. Personal adjustment is recommended. There should not be any water condensation in the mask.
The air coming from CPAP can be cold and this can be corrected by ensuring the room temperature is adequate or by using a heated humidifier.
Sometimes nasal allergies can be exacerbated by CPAP. Known allergens in the room should be removed. Frequent vacuuming may be required and you should raise the CPAP blower off the floor. Elimination of animals from the bedroom may be helpful. Ensure that the CPAP filters are cleaned and changed frequently. An in-line fine particulate filter may be useful (Respigard-II-Marquest Medical Products) -- it must be put in the line before the humidifier. Use only distilled water in the humidifier. Try with or without humidification and with or without heat if it is a heated humidifier.
An oral antihistamine taken before sleep or the use of a nasal antihistamine or nasal steroid spray may be helpful. The effect of nasal steroids may take weeks.
Use a humidifier either heated or regular pass-over humidifier. Obtain a nasal saline spray to use before sleep at night.
Check for nasal allergies and if so consider steps above.
Use a humidifier, preferably a heated humidifier. Use a saline spray before sleep. Consider putting a small amount of ointment in the nostrils, such a Boroleum or Vaseline.
The mask should not be too tight. If it needs to be very tight for an adequate seal, try a different type of mask -- there are many types available. Use a forehead spacer to take the pressure off the bridge of the nose. Consider using Nasal Pillows to reduce the mask contact with the skin.
Make sure you have a hypoallergenic mask made of silicone. Consider using a CPAP Nasal Pillows to reduce mask contact with face.
Any of the above recommendations may be helpful. In addition ensure that the CPAP pressure is optimal -- contact your sleep specialist. Try a chin strap and consider using Nasal Pillows instead of a mask.