An ENT may be able to help if it's a physical problem. Tongue placement at the roof of your mouth is paramount though. It will help open the nasal sinus. If you can't put your tongue up there, you may be tongue tied, and can look into a frenectomy to untie it. A myofunctional therapist will then help you learn how to properly strengthen and hold your tongue in the right place, as well as swallow properly.
It might sound crazy, but mouth breathing is linked to ADHD and all kinds of issues, likely due to lower nitric oxide levels and less stimulation of the pituitary gland. Expect the field to grow in the next decade. Lots of us are now having problems because of the reduction of breast feeding, amongst other things.
Thanks for the info - seeing an ENT is also on my todo list. I never realized this was an issue until recently, but looking back I've always been a mouth breather.
One night a few weeks ago I tried the method of taping my mouth shut before going to sleep. I woke up the next day feeling super sick and lightheaded, presumably due to lack of oxygen. There definitely seems to be an issue with my nose breathing.
Yes, taping is a great strategy but if you have bad tongue placement or just a physical nasal airway restriction, you might not be ready. ENT is your first stop, in my experience. Schedule it up!
It's not even a question of IF for those who are into this stuff. It's really a question of WHY for the researchers. But for those in the field, the solution is simple and you don't need to know the why, you just work around it (by nasal breathing!)
Here's some more that are more about the sleep apnea side of things:
Point being: before you think you (or your kid) is "ADHD", see to it that they are breathing and sleeping properly. They're just so tired they become irritably unstable and unfocused. Lack of sleep = kids are a mess