My wife had noticed I had the classic symptoms at night of stopping breathing, so rather than waste time going via my GP, I just rang up Spire* and got asked to choose between a couple of consultants. The website had information about them and their specific expertise, so after making a choice, I got a fairly quick appointment within a couple of weeks.
The consultant initially didn't believe I could have sleep apnoea as I'm not overweight, don't smoke and rarely drink. It was only after sending me home with the kit for a couple of nights that he admitted he was quite shocked seeing the results, as apparently I was having between 30-60 episodes an hour with no breathing, but it was only due to being fairly fit through cycling, that I wasn't suffering excessive tiredness during the day.
I tried the CPAP machine but just couldn't get on with it. I can't sleep in a room with any noise, not even a ticking clock. The machine itself wasn't noisy, but the airflow itself was, meaning it took ages for me to get to sleep, plus if I nudged the mask in my sleep, the escaping air woke me up. On a couple of occasions I also found I'd partially restricted the hose with my arm on it, so again that woke me up.
I've ended up with a low tech solution consisting of a heart rate monitor strap onto which I've attached an old aerosol can which then sits across my upper back, making it very uncomfortable to lie on my back. This means when I'm asleep, I don't roll onto my back, so no apnoea.
* I think you'll probably get similar results from any of the major UK private health insurers.