@jc76 After extensive investigations by ENT and GI for potential reflux and post nasal drip, i was also told that it could be nerve related having found no other cause - having tried the various saline sprays and omeprazole nothing has made a difference. However with new research about our gut and brain biomes being linked, i have also discovered that the nasal biome and gut biome are also linked and so i decided to do a 'gut reset' cutting out gluten, dairy and other possible irritants (i have no known allergies) - and i started to take L glutemin powder in water first thing in the morning and B12 once a day and magnesium glycinate before bed and did 4 sessions of acupuncture - an ancient practice that has understood for thousands of years that we must treat the body in a more holistic way. I can honestly say that for first time in over 10 years of relentless and excessive thick phlegm this regime has greatly helped to reduce my phlegm production - by chance i have also found that the cheapest of ingredients CLOVES has greatly helped to alleviate the phlegm when i have a flare up - i go to bed sucking on one or two cloves at night and carry them around in my bag for whenever i feel the phlegm rising in my throat during the day. I hope this helps as I have found it so debilitating over the years and so very difficult to explain to others how it impacts on your life both day and night.