Let us presume that the “older” person is the same as they were when they were younger in terms of weight and health problems.
As you probably know, as you get older all of your “bits” tend to get less elastic and less toned and droop a little.
Well, that also applies to your muscle tone, but not only to the muscles that you can see from the outside, but also to internal muscles.
Your upper airway that you need to pass air in and out of to breathe is surrounded by muscle that has now started to droop a little.
This drooping wall of muscle falls against your airway as you sleep and pushes it to a narrower size.
Air travel from your breathing needs to increase in speed to rush through the narrower opening.
The increased air velocity causes soft tissues, such as your soft palate (which also become less toned as you age and more “flappy”) to vibrate as the faster air rushes past which results in the noise that we know as snoring.
Apart from a possible myriad of health contributory factors, one of the main factors that also cause older people to snore is weight gain.
Not so much total body fat gain, although this will promote an increase in internal fat cells as well, but fat gain on the inside of your throat.
More fat cells in the throat, means less space for your airway to remain unrestricted and the result is pretty much the same as with the muscle scenario above.
Usually, it is a combination of both of these factors (muscle drooping and fat cell increase) that causes many older people to start to snore in their later life.