by Malavi Sivakanesan • 10 February 2025 • 5 min read
Dry mouth, or xerostomia, is a condition where the salivary glands fail to produce enough saliva to keep the mouth moist. And since saliva plays a very important role in digestion and helps prevent infections, the lack of it can be problematic. You can experience difficulty in chewing, swallowing, or even speaking. However, while occasional dryness may not be a concern, persistent dry mouth can be a sign of some underlying disease. It can also drastically increase the risk of cavities, gum disease, and bad breath. Knowing about the causes is the first step towards getting it treated, so read on to know about the common dry mouth causes and when it’s time to seek medical attention.
Causes of Dry Mouth
Causes of dry mouth xerostomia can range from simple dehydration to even autoimmune disorders. Here are all xerostomia causes:
Dehydration
Dehydration occurs when your body loses more fluids than it takes in, making it difficult to function properly. This can happen due to excessive sweating, diarrhoea, or simply not drinking enough water throughout the day.
When the body is dehydrated, it prioritises water for essential functions like maintaining blood circulation, and then obviously, the amount available for saliva production will be reduced.
Since saliva is made mostly of water, dehydration can significantly reduce its flow, leading to a persistently dry mouth.
Medication
Certain medication also causes sudden dry mouth as it can interfere with the body’s ability to produce saliva. This happens because some drugs affect the nervous system or reduce fluid retention. This reduction, in turn, decreases saliva flow.
The severity of dryness depends on the type of medication, dosage, and individual response. Common medicine causing dry mouth include antidepressants, antihistamines, diuretics, and painkillers.
These medications are generally used to treat conditions like allergies, high blood pressure, and mental health disorders. If dry mouth becomes bothersome, discussing saliva substitutes for xerostomia with a healthcare provider may help.
Medical Conditions
Certain medical conditions can also directly or indirectly lead to dry mouth by affecting the salivary glands, nerves, or overall fluid balance in the body. Some diseases interfere with how the body produces and regulates saliva, while others contribute to dehydration, making dryness worse.
Here’s what disease cause dry mouth:
- Diabetes: Diabetes is one of the common diseases that cause dry mouth because high blood sugar levels can cause excessive urination. This leads to dehydration and reduced saliva production.
- Sjögren’s Syndrome: An autoimmune disorder that specifically attacks moisture-producing glands, including the salivary glands. It can cause severe dryness in the mouth and eyes.
- Parkinson’s Disease & Alzheimer’s: These neurological disorders can disrupt nerve signals responsible for saliva production, leading to persistent dry mouth.
- HIV/AIDS: The disease itself, along with certain medications used for treatment, can affect the salivary glands and reduce saliva flow.
- Stroke: A stroke can damage nerves that control saliva production, resulting in long-term dry mouth symptoms.
- Rheumatoid Arthritis (RA): Though primarily affecting joints, RA is linked to Sjögren’s syndrome, which significantly reduces saliva production.
Aging and Xerostomia in Elderly
As people age, their bodies undergo various changes, including a natural decline in saliva production.
While ageing itself isn’t what causes xerostomia, the combination of age-related changes and the above-mentioned diseases makes it more common in older adults. Thus, Older adults with dry mouth should prioritise preventive dental care by visiting their dentist regularly.
Lifestyle Factors
Lifestyle habits can significantly contribute to dry mouth by affecting saliva production and overall dental hygiene. These factors may not cause xerostomia directly but can make the condition worse over time:
- Smoking & Tobacco Use: Tobacco products, including cigarettes and chewing tobacco, reduce saliva flow and irritate oral tissues. Long-term use can lead to chronic dry mouth and increase the risk of gum disease.
- Alcohol & Caffeine Consumption: Both alcohol and caffeine have diuretic effects, meaning they draw moisture from the body. Drinking excessive coffee or alcoholic beverages can contribute to dehydration and worsen dry mouth.
- Mouth Breathing & Snoring: Breathing through the mouth, especially while sleeping, dries out saliva faster than normal. Snoring or conditions like sleep apnea can make this issue more persistent.
- Dietary Choices: Foods high in sugar, salt, or acidic content can worsen dry mouth symptoms by irritating the mouth and drawing moisture away from the tissues.
When to Seek Medical Help?
If your mouth still feels dry even after drinking plenty of water and trying all xerostomia remedies, it might be time to see a dentist. Persistent xerostomia can lead to bigger problems like cavities, gum disease, and frequent mouth infections.
Some other common signs to watch out for include cracked lips, trouble chewing, and a constant dry or burning sensation in your mouth.
A dentist can figure out what’s causing your dry mouth and suggest the right xerostomia treatments to help. Schedule an appointment with Complete Smiles today for a thorough checkup and get your dry mouth under control before it leads to something more serious.
Malavi Sivakanesan
Malavi Sivakanesan is the principal dentist and co-founder at Complete Smiles in Harrow, Greater London. She is responsible for establishing the Complete Smiles brand throughout the United Kingdom and Europe and has 5 successful practices under her strong leadership.