The only thing scarier than a stroke is having one and not even knowing it.

It's the so-called "silent" stroke -- given the name because it comes and goes with no symptoms.

Not on the outside, anyway.

But in the inside, a silent stroke can tear away at your brain, causing the kind of serious damage that can increase your risk of a not-so-silent stroke down the road.

And since your brain has already suffered stroke-related damage, you'll face a much greater risk of disability afterwards.

A silent stroke can strike anyone, anytime, anywhere -- but the latest research finds one set of people who have a much higher risk than everyone else: The millions of people who suffer from sleep apnea.

As I'm sure you know by now, sleep apnea robs you of your breath as you sleep, sometimes for a minute or more and sometimes for hundreds of times a night.

When you don't breathe, oxygen doesn't make it into your body. It doesn't get to your heart, boosting your risk of heart problems -- and it doesn't get to your brain, which is why it's already a well-known risk factor for strokes.

In a new look at 56 stroke patients, German researchers found that 51 -- or 91 percent of them -- suffered from sleep apnea, with the apnea patients also more likely to show the kind of white matter damage that indicates they've had a silent stroke.

Apnea patients who had five or more episodes a night had the highest risk of silent stroke -- and when the "real" stroke came, they were also more likely to suffer from disability after being discharged from the hospital.

Strokes -- silent or otherwise -- are notoriously tough to predict. But apnea is a lot easier to figure out: If your spouse has seen you gasping in the night or heard steady snores mixed with utter silence, there's a good chance you have it.

A night in a clinic can confirm it -- but you don't need a sleep lab to start turning it around. In most cases, apnea is linked to obesity -- and if you simply lose the weight, it'll go away on its own.

You'll not only slash your stroke risk and sleep better at night... you'll feel better all day, too.