Thick saliva can result from dehydration or breathing through the mouth. However, it can also indicate a more serious condition, such as Sjögren disease or cystic fibrosis.

Finally, several medications and certain cancer treatments can cause thick saliva.

This article takes a look at the different causes of thick saliva. It also details how to manage thicker saliva and the importance of oral health.

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There are many possible causes of thick saliva.


Dehydration can cause thicker saliva. This is because when the body is dehydrated, it spares less water on saliva.

Dehydration can arise for many different reasons. Mostly, dehydration arises from not drinking enough water or other fluids.

Dehydration may be more likely if people lose fluids from the body. This can happen because of sweating due to hot weather or exercise. A person can also lose fluids and become dehydrated through vomiting and diarrhea.

Mouth breathing

Research has shown that breathing primarily or solely through the mouth can lead to thick saliva.

This is because mouth breathing exposes the mouth to air, causing it to dry out.

Cancer treatment

According to the American Cancer Society (ACS), some cancer treatments can lead to thick saliva. These include:

These treatments can damage the glands that produce saliva. As a result, the glands can only produce reduced amounts of saliva. This saliva will dry out after, making it thicker and stickier.

Sjögren disease

As a 2023 review explains, Sjögren disease is a serious autoimmune condition. This means that it arises when an individual’s immune system mistakes their own cells for harmful pathogens.

Sjögren disease causes inflammation in the salivary glands, which produce saliva. This ends up causing a dry mouth and thicker saliva. Sjögren disease can also cause dry lacrimal glands, which produce tears.

Cystic fibrosis

Cystic fibrosis is a genetic condition that causes mucus buildup in the lungs and digestive system.

However, research has shown that cystic fibrosis can reduce saliva production. This can lead to thick saliva. It can also lead to inflammation, a burning tongue, and problems tasting or eating food.


Several medications can cause thick saliva as a side effect. Indeed, a 2023 paper discusses how some medications reduce saliva production in at least 10% of cases. These medications include:

According to a 2023 article, there are several ways to get rid of thick saliva. These include treating any underlying condition or swapping medications, if possible. They also include the following steps:

  • not breathing through the mouth
  • frequently sipping water
  • sucking on sugar-free candy
  • avoiding dehydration
  • avoiding or reducing caffeine, tobacco, and alcohol
  • using artificial saliva

If none of the above work, doctors can prescribe medications. These include the FDA-approved pilocarpine and cevimeline, which can stimulate salivation.

The same 2023 article also mentions the importance of good oral health for people with thick saliva. Good oral hygiene involves routine brushing and flossing of the teeth. It also involves regular professional dental care.

These things are important because thicker salvia can contribute to worse oral health. This condition can lead to the following issues:

  • dental caries
  • enamel erosion
  • bad breath
  • fungal infections

Because saliva plays a vital role in starting digestion, people with thick saliva may also experience malnutrition.

Anyone who is worried about thick saliva should contact a doctor. If thick saliva keeps coming back or occurs in the absence of dehydration or mouth breathing, it could indicate a serious condition.

There are many possible reasons why people may have thick saliva. Breathing through the mouth is one. Dehydration is another, which might arise due to heat, exercise, or an underlying health condition.

Some diseases also cause thick saliva. This is the case with Sjögren disease, which reduces the production of saliva and tears. Cystic fibrosis can also cause issues with saliva production.

Finally, several medical treatments can cause thick saliva. These include chemotherapy and radiation therapy — both cancer treatment options.

However, pain medications, antidepressants, and blood pressure medications can also cause thick saliva. Many other pharmaceuticals can do the same.