My mom (97) has begun to have mucus build up periodically. Any ideas?

Dehydration causes excessive mucus.. When my Mom was dehydrated she has so much mucus flowing out her nose and drool...

Allergies are truely awful this year.. both hubs and I are hacking alot, and so are alot of my coworker. Have you had her checked for this?

Ask her doctor about ordering a suction machine through Home Health. It's a small/medium portable machine that plugs into the wall socket, not very heavy at all. My father had ongoing secretion/mucous issues because of medical treatment to his jaw.

Increase hydration. Also, at 97 and with Alzheimer's your mom may not have the throat and chest muscles she once had to bring up the junky stuff.

There's also a medication although for the life of me I can't remember the name of it. Anyway, this medication is given under the tongue and it thins out the secretions so they're not rattling around in the chest and throat. It works very quickly too, within minutes. I'm sure your mom's Dr. knows it.