What does this mean?
Saliva flow naturally drops at night. If hours of breathing through the mouth are added to that, the inside of the mouth dries out by morning. Lips sticking together, the tongue sticking to the palate and waking up to drink water are typical parts of this picture. The dryness eases within an hour or two of getting up, because saliva flow increases again during the day.
The telling detail is the timing. If the dryness is heaviest when you wake and lightens as the day goes on, the source is most likely your breathing at night. If the dryness lasts all day and is uncomfortable while you eat and speak as well, causes that affect the salivary glands come to the fore: the medicines you take, a history of radiotherapy to the head and neck, or conditions such as Sjögren's syndrome. Because these two stories lead down different routes, it matters that you describe what time of day the dryness occurs.
Dryness at night is not only an uncomfortable feeling. Saliva buffers acid and protects the enamel at night too; when that protection falls away, decay can speed up, particularly at the gum margins and on the root surfaces. In people who wear dentures, dry mucosa makes a suitable ground for sore patches and thrush. When a dentist sees these traces in the mouth, this is usually the point from which the questions about sleep and breathing are opened.
Behind a dry mouth that belongs to the morning alone there is most often a night spent breathing through the mouth, but causes that reduce saliva flow can be added to the picture as well. The headings below bring these causes together.
Likely causes
What helps at home?
- Keep water by your bed; when you wake in the night, choose water rather than a sugary or acidic drink.
- Brush with a fluoride toothpaste before bed, and do not rinse your mouth out with plenty of water after spitting the toothpaste out; the thin layer left on the surface works through the night.
- If the air in your bedroom is very dry, try using a humidifier; the dryness becomes more noticeable in the months when the heating is on.
- Draw up a list of the medicines you take and show it to your doctor. Some blood pressure, allergy, bladder and mental health medicines reduce saliva; do not stop your medicine on your own decision.
- If the dryness comes with snoring and with pauses in breathing that someone else has seen.
- If your eyes are dry as well, and the two together have lasted for weeks.
- If decay has appeared in several teeth, or fillings have chipped at the edges, within a short space of time.
- If white patches that do not rub off, a burning feeling or a change in taste have been added in your mouth.
- If the area under your jaw, or in front of your ear, becomes swollen and painful.
Frequently asked questions
- Is a dry mouth in the morning proof of snoring?
- On its own it does not count as proof, but it is a strong clue. When your mouth stays open at night, the dryness and the snoring can arise from the same cause. If daytime sleepiness, or pauses in breathing that someone else has seen, accompany the dryness, being assessed from the sleep side is advised.
- Does drinking water at night solve the dryness?
- Water gives relief for the moment, but it does not take the place of saliva; the buffering and protective components of saliva are not found in water. Waking up to drink also breaks your sleep. Lasting relief therefore depends on finding the cause of the dryness.
- Do dry mouth sprays and gels work?
- Moisturising gels and sprays can ease the discomfort, and can give comfort at night, particularly in people who wear dentures. But they do not remove the cause of the dryness. Choosing sugar-free products and keeping up your dental check-ups matter in this period.
This content is for general information and does not replace an in-person examination. Symptoms overlap between conditions, and a diagnosis can only be made clinically.