If just the thought of losing your breath as you sleep is frightening, you should see what it looks like when it really happens.

This video of a man with sleep apnea was posted on the Web site of the British newspaper The Daily Telegraph.

In the video, the man stops breathing for 40 seconds in his sleep. But what's even more frightening is what you don't see: He also operates heavy machinery for a living--- and his apnea has left him tired at work.

This can't end well.

And this video shows just one apnea incident -- but patients who have the condition can stop breathing dozens and even hundreds of times each night, depriving the heart and brain of essential oxygen.

One new study finds women who battle the condition have a 350 percent higher risk of dying of heart disease -- and other studies have found similar risks for men. Along with heart problems, apnea has been linked to dementia, stroke, diabetes and more -- with another new study showing how apnea can even boost your risk of sudden deafness by nearly 50 percent.

In the short term, some apnea patients use continuous positive airway pressure, or CPAP machines -- uncomfortable oxygen masks that come with risks of their own, and that's if you can even manage to keep them on all night.

In one study, only two out of 35 patients could tolerate them long enough to see a benefit.

But even if you can handle wearing an oxygen mask all night, it's not a permanent solution.

In many cases, apnea is caused by obesity -- so if you're overweight and your spouse has seen you lose your breath in the night, drop those extra pounds ASAP and chances are you won't need CPAP.

And if you've gotten too big over the years and find yourself not as rested in the morning as you used to be, you might have the condition, too. Other warning signs to watch for: headaches, waking up with a dry mouth or sore throat, frequent nighttime bathroom trips and mood changes.

A night in a sleep clinic can help you figure it out -- but in the meantime, lose the weight anyway. Even if it's not causing sleep apnea -- yet -- it's not doing you any favors.