I have also been using a CPAP for 2 months and have experienced pain that I believe is related to my achalasia.
I started having symptoms of achalasia when I was 7 or 8 years old and was on death's door when I was finally diagnosed at 14 (I had only gained 5 pounds over 6 years and weighed only 76 pounds when I had my open Heller Myotomy at 15). That was in 1985 and it honestly saved my life. Other than GERD I only notice issues related my achalasia a few times a year, but I can deal with that.
However, since starting CPAP I have experienced intense pain right around where my lower esophageal sphincter is. It has happened twice (once each month). After the first time, the doctor lowered my pressure from a max of 15 to 11. I'm waiting to hear back from him now regarding the second episode. The pain feels like an extreme muscle tear/stretch and it hurts to cough, laugh, or breathe very deeply. Last time it took a week to recover from it and I'm on day 3 this time. I can get through the day ok but the nights are horrible because any little movement causes pain. I can't use the CPAP when this happens.
I was wondering, has anyone else experienced this same thing? If so, what did you do for relief.
@andreafl and @rick336, There are others in the CPAP discussions who have posted about problems with reflux and gerd. I did a quick search but you may want to change the search words for specific symptoms. Here's what I found - https://connect.mayoclinic.org/search/comments/?search=CPAP%20causing%20reflux.
Here's an older research article from 2007 on the topic:
-- The impact of continuous positive airway pressure on the lower esophageal sphincter:
https://journals.physiology.org/doi/full/10.1152/ajpgi.00476.2006