CPAP and Dry Mouth – What to Do About Waking Up with a Dry Mouth

Snorts and snores suck moisture out of your mouth and throat. When you cannot breathe because the airway from your nose to your throat is closed, oxygen levels in your bloodstream fall. Your heart pumps harder and faster to try to circulate the oxygen you have left in your bloodstream to your brain and other vital organs. Finally enough pressure builds up with your exhalation that your mouth explodes open with a snore or a snort, and for a few seconds or a few minutes, you breathe much faster to make up your oxygen deficit. During that period of frantic but unconscious activity, your body temperature goes up, not down. And the fast flow of air over your palate sucks out moisture.

Sleep apnea also causes dehydration through urination. If you watch television in the USA, about once or twice an hour, on many networks, you can see some advertisement for a product that stops sudden urination by acting as a selective tranquilizer for the nerves that control the bladder. Unfortunately, none of these products will help you control nighttime urination if you have sleep apnea.

The reason so many people who have sleep apnea have to get up to go to the toilet in the middle of the night has nothing to do with their bladders. It more than likely has nothing to do with drinking too much water before bedtime, taking a diuretic, or some underlying anxiety or emotional condition causing a “nervous bladder.” It has everything to do with the fact that when you have sleep apnea, your kidneys make more urine at night. Here are the reasons why.

Your kidneys are very important in the regulation of your blood pressure. If there is too much fluid in your circulatory system, your blood pressure could go too high. If there is too little fluid in your circulatory system, your blood pressure could go too low. The kidneys remove water from the circulatory system faster or slower, depending on the volume of fluid needed to maintain healthy blood pressure. Since you don’t drink while you are asleep, the kidneys make less urine at night, keeping your blood pressure in a healthy range, that is, unless you have sleep apnea.

The resistance at the top of your breathing airway that causes sleep apnea makes your chest muscles work a lot harder to breathe. They have to work to pull air into the chest cavity, expanding it without air coming in. This creates lower pressure around the heart that pulls more blood into the heart.

The upper right chamber of the heart, the right atrium, has special sensors that send a hormonal signal to the kidneys when blood pressure is going to high. When you have sleep apnea, the added flow of blood to your heart is interpreted as “too much fluid.” The kidneys get a dose of atrial natriuretic hormone from the heart, telling them to make more urine to lower your blood pressure. The kidneys comply by making more urine, and the sleep apnea sufferer may wake up once, twice, three times, or more to void during the middle of the night.

You wake up multiple times during the night, and your whole body dries out. Your mouth dries out. Your throat dries out. Your eyes dry out. And your skin dries out.

Your CPAP treatment program is supposed to take care of both problems. If it doesn’t, the very first thing you need to do is to consult your doctor about changing the settings on your machine.