The most common way is through an overnight sleep study at an accredited sleep lab. There are many here in the area that we can recommend you to.
We also have home test device here in the office. They don't screen quite as many factors as an overnight sleep lab does when you're observed, but they are very accurate in determining a great screening level of what is going on with your oxygen levels and apneas, which is not breathing for more than 10 seconds at night - recording these kinds of things. So they can give you a great idea of where you're at.
Your bed partner can help you out a lot with sleep apnea. Obviously, snoring is a very common occurrence and there's a very high correlation between snoring and sleep apnea. If your bed partner notices that you do not breathe for quite some time or you gasp or you've been short of oxygen and your body is trying to catch up. If your restless, then other symptoms that you yourself will notice - if just you don't wake up feeling refreshed, you're fatigued easily, daytime sleepiness, afternoon sleepiness, sleepiness while driving. All these can be indications that you're not getting adequate sleep that's being interrupted.
High blood pressure is very commonly associated with sleep apnea. If you're gaining weight for no particular change in diet or whatever, often times that can be a cause of sleep apnea because we're not getting any adequate sleep. Our hormone levels and insulin levels can be upset and we're not having a metabolic rate that we normally would. So there's a number of factors that can occur.
But if you notice any of these, I certainly encourage you, whether it's with us or whoever, is to be tested because I think the statistics are most common that people have sleep apnea up to 10 years before most people are diagnosed, and those 10 years can have a great long term impact on your health.