Oh, that's annoying. That's happened to me as well! Do you have allergies or anything? Let me ask you the tough question of other symptoms like low grade fever or dry cough? The covid-19 virus is out there! I have what you describe a lot like on the tail end of a cold. Drives me crazy! Two things that I've read really help is lots of hydration. Drink extra water as it thins your bodies secretions. Also, you can take OTC Mucinex which thins them as well. Helps keep the gunk moving. https://www.medicalnewstoday.com/articles/319636#symptoms Dry air can cause it if you are all of a sudden in side a bit more. ?? And a humidifier can help. Psuedophedrine, another OTC product (but usually behind the pharmacist's counter) is known to dry up the mucus too. So, you could try that. I find it a bit activating so take it during the day. Now, if you have anything else coming on like shortness of breath, dizziness, confusion, etc. then you should get checked out. Shortness of breath also has to do with oxygen in our blood that we need. Do you live near a covid outbreak area?
Can you try and experiment for me please? Don't do if on blood thinning drugs but can you drink 2 to 3 glasses of Pineapple Juice a day. My Mum has MND and this works a treat. This phelgm is an issue in this condition :)
Though it may not feel like it, it’s likely sinus drainage. Nothing has beaten honey for me. It should be local or area honey. Mine came from a city about 150 miles away. His nurse practitioner surprised my doctor by solving my problem with honey (1 rounded tablespoon). It sometimes didn’t return for a day or even more. I missed my granddaughter’s h. s. graduation because I thought it sounded silly.
I also discovered the congestion returns or increases when I drink milk, not necessarily in foods.
The humidifier can help if a dry throat or nose is part of the problem. It can indeed get very scary.
I would suggest you get tested for GERD. Gastric Reflux. The acid from you stomach leaks into you throat causing irritation and phlegm.