Rachel MacPherson is a health writer, certified personal trainer, and exercise nutrition coach based in Montreal.
Dr. Danielle Weiss is the founder of the Center for Hormonal Health and Well-Being, a personalized, proactive, patient-centered medical practice with a unique focus on integrative endocrinology. She enjoys giving lectures and writing articles for both the lay public and medical audiences.
Dry mouth, or xerostomia, can be an uncomfortable side effect of diabetes that can lead to complications such as gingivitis over the long term if left untreated. Since saliva protects your teeth (helping to prevent decay) and also improves digestion and the ability to taste food, it’s essential to get it treated.
Sometimes dry mouth is a symptom of undiagnosed or improperly treated diabetes. Knowing the symptoms, causes, and treatments of dry mouth can help you address the issue with your healthcare provider for the best outcome.
eyecrave / Getty Images
Dry mouth is a condition in which the salivary glands in your mouth do not make enough saliva. The lack of saliva leaves your mouth feeling uncomfortably dry. Symptoms include:
High blood sugar, or hyperglycemia, is common in people with diabetes mellitus (types 1 and 2) that isn't well managed. High glucose levels can cause the symptom of dry mouth, although healthcare providers aren’t quite sure why.
Other oral symptoms of high blood sugar are:
Fatigue, blurred vision, and headaches may also occur.
If you have high blood sugar that isn’t being well controlled, your healthcare provider will be able to help you come up with a plan for better eating habits and medication should you need it.
The fluids lost from high blood sugar can make you very thirsty, so be sure to drink plenty of water. It’s best to avoid foods and drinks with a lot of sugar content, like:
If your blood sugar goes above 180 to 200 mg/dL, it can cause kidney, heart, vision, and nerve damage. If left untreated, coma and death are risks.
Not getting enough fluids can cause dry mouth from dehydration. Liquids are necessary for your mouth to produce enough saliva.
Diabetes insipidus—a less common form of diabetes in which the kidneys have a difficult time preventing water excretion—can cause constant thirst and dehydration.
Similarly, diabetes mellitus can cause constant thirst and an increased need to urinate, which leads to dehydration and dry mouth.
Dry mouth due to dehydration for people with diabetes can often be controlled with medications. Drinking enough water to match the water loss through urination is also essential.
Diabetes insipidus causes the kidneys to be unable to concentrate urine effectively and to excrete a large amount of dilute urine.
With types 1 and 2 diabetes, blood sugar can build up and cause problems for your kidneys while they work hard to manage the excess blood glucose. When this happens, water is pulled from your other bodily tissues, causing you to feel thirsty.
You may also:
Managing your condition with medications and being sure to drink enough water is essential.
If you are overdue for a kidney check (24-hour urine), schedule an appointment/call your healthcare provider about getting a collection jug and set aside a day to do it. Consider asking for a referral to a nephrologist.
Certain medications used for diabetes can cause dry mouth, including Metformin. ACE (angiotensin-converting enzyme) inhibitors, which are used to treat hypertension and diabetes, can cause dry mouth.
You may be able to switch your medications if they cause you dry mouth. Speak to your healthcare provider about this option.
Always consult with your healthcare provider before stopping any medication.
Dietary ketosis is not the same as diabetic ketoacidosis but is intentional ketosis caused by following the keto diet. Dry mouth is a common side effect of this diet.
The keto diet is also a popular choice for those with type 2 diabetes. The dry mouth with dietary ketosis is due to dehydration from water loss. Water loss happens when glycogen is being excreted from the blood due to a lack of carbohydrates.
Ending your keto diet can help prevent dry mouth, but for those who do not wish to change their diet, focusing on eating foods that are keto-friendly and contain a lot of water is a good strategy. Try fruits and vegetables like:
People with kidney disease have an increased risk of needing dialysis if practicing the keto diet since the additional ketones that their renal system has to process cause the kidneys to become overworked. Speak to your healthcare provider before changing your diet.
If your body’s cells do not get enough glucose needed for energy, the body will use ketones instead. When this happens, ketones can build up in the blood and make it more acidic.
For people with diabetes, this can mean that your illness is not being well controlled, and you could get very sick. This condition most often occurs in people with type 1 diabetes, although it can happen in those with type 2.
You should check your urine for ketones when your blood glucose is more than 240 mg/dl. Do not exercise if your urine shows ketones and your blood glucose is high. Contact your healthcare provider for advice.
Diabetic ketoacidosis can become life-threatening. Early signs include:
If you experience these symptoms, call your healthcare provider. Once vomiting occurs, a life-threatening condition can develop quickly. Call emergency services immediately.
Dry mouth due to diabetes or other causes can be treated with some other remedies as well. Try the following tips:
A dry mouth can be uncomfortable and lead to dental issues and other health problems if left untreated. You can take some steps to remedy dry mouth at home, but you should also speak to your healthcare provider about this symptom to get help determining the cause and a treatment that is appropriate for you.
National Institute of Diabetes and Digestive and Kidney Diseases. Diabetes, gum disease, & other dental problems.
MedlinePlus. Diabetes insipidus.
Alsakran Altamimi M. Update knowledge of dry mouth- A guideline for dentists. Afr Health Sci. 2014;14(3):736-742. doi:10.4314/ahs.v14i3.33
Bostock ECS, Kirkby KC, Taylor BV, Hawrelak JA. Consumer reports of "Keto Flu" associated with the Ketogenic diet. Front Nutr. 2020;7:20. Published 2020 Mar 13. doi:10.3389/fnut.2020.00020
David S Ludwig, The Ketogenic diet: evidence for optimism but high-quality research needed, The Journal of Nutrition, Volume 150, Issue 6, June 2020, Pages 1354–1359, doi:10.1093/jn/nxz308
Northwestern Medicine. What you need to know about keto.
American Diabetes Association. DKA (ketoacidosis) & ketones.
National Institute of Dental and Craniofacial Research. Dry mouth.
Rachel MacPherson is a health writer, certified personal trainer, and exercise nutrition coach based in Montreal.
Thank you, {{form.email}}, for signing up.
There was an error. Please try again.
By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyze site usage, and assist in our marketing efforts.