text: A That drooling can have several causes, and excessive drooling even has a medical name: ``sialorrhea.''\n\nWe actually make more saliva during the day, but we also swallow more often when awake. In most adults, both saliva production and swallowing slow during sleep, and drooling does not become a major problem, says Dr. John Winkelman, associate director of the Sleep Disorders Service at Brigham and Women's Hospital.\n\nSeveral things can cause nighttime drooling. Some medications increase saliva production. Your sleep posture can also contribute. When you lie on your back, saliva pools in the back of the throat and often causes a swallowing reflex that prevents drooling. But when you lie on your side, saliva can pool in your cheek -- or flow onto your pillow.\n\nYou're also more likely to drool if you breathe through your mouth instead of your nose. That happens to people with colds, or those with a deviated septum who must keep their mouths open to get enough air.\n\n``In general,'' says Winkelman, ``drooling is not a problem and people don't need treatment -- although they may have to change pillowcases in the middle of the night.''\n\nOccasionally, excessive drooling can result in breathing saliva into the lungs. This can be dangerous, since saliva contains much of the bacteria found in the mouth, and can cause repeated bouts of pneumonia. In this case, treatment to stop the drooling may be necessary, says Winkelman. Drugs can cut the flow of saliva. Allergies or nasal obstructions that cause people to sleep with their mouth open can also be treated.\n\nBut in general, drooling is nothing to lose sleep over.