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4 common causes of dry mouth

Dry mouth (xerostomia) is more common than you’d expect. It’s estimated that 1 in 4 people suffers from dry mouth. But what is it and why does it happen?

In a nutshell, dry mouth is a person’s experience of their mouth feeling dry. This could show up as having difficulty eating dry foods like bread or crackers, having dry and cracked lips, and waking up feeling thirsty at night. 

Some symptoms particular to dry mouth, particularly at night, are:

  • Feeling unusually  thirsty when you first wake up
  • Having a dry, scratchy throat 
  • Having a sticky build-up of saliva in your mouth, the corners of your lips, and/or on your tongue
  • Having bad breath in the morning that persists through the day

Common causes of dry mouth


Many people experience dry mouth as they get older. This can be due to a number of factors including medication use and illness, however, it is often simply a byproduct of our ageing bodies. 

Mouth breathing

Mouth breathing is exactly what it sounds like – when you breathe through your mouth instead of through your nose. You might notice this when you have a cold or allergies and your nasal passages are clogged up. Mouth breathing, though, can also be a warning sign of sleep-disordered breathing. As always, contact your doctor for a sleep test if you think this might be the cause. 


Dehydration happens when you are drinking less than you are expelling. For example, if you aren’t drinking enough water while exercising on a hot day or if you have diarrhea. There are some underlying issues that could cause prolonged dehydration so be sure to talk to your doctor if it persists.

Lifestyle choices

Drinking coffee and tobacco use are common culprits of dry mouth. Coffee drinkers may experience dry mouth due to the dehydrating effect of caffeine or tannins, a molecule found in coffee. Similarly, the long-term effects of smoking can include the production of less saliva than you would expect in a non-smoker. 

If any of these symptoms or causes sound familiar to you, you might want to talk to your dentist about the best ways to treat your dry mouth. Book an appointment today: 

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