If you’re curious to try this, read James Nestor’s book Breath, do yoga with breathing exercises, or see a physical therapist. It takes time to fix these structural issues, but you can literally change the shape of your nose, palate, and jaw from just practice.

Here’s a quick exercise you could try. Sit up, relax your body, breathe in through your nose, and feel the breath move up your nose, down to the base of your skull, down your neck, and then as far down your spine as you can. The air isn’t literally moving through these areas, but you should feel a current of sensations moving roughly along that path. As you breathe out, follow the current in the opposite direction. As you tune into this current, your neck and back will naturally straighten a bit, it should feel very natural and even pleasant. Keep your body relaxed and allow your neck and back to align with this current. If you keep doing this regularly it should help improve your posture and breathing. This is basically a pranayama / yoga breathing exercise. If it feels painful, definitely stop and try physical therapy or working with a hatha yoga instructor who can give you more guided instruction.

I used to snore so badly it sounded like, without much exaggeration, a dying elephant. I only did this exercise for a couple years and it slowly improved over that time, and now I sleep quietly.