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.

There are many possible causes of thick saliva.
Dehydration
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
Mouth breathing
This is because mouth breathing exposes the mouth to air, causing it to dry out.
Cancer treatment
According to the
- chemotherapy
- radiation therapy to the head or neck
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
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,
Medications
Several medications can cause thick saliva as a side effect. Indeed, a 2023 paper discusses how some medications reduce saliva production in
- Anticholinergic agents: These include atropine, belladonna, and oxybutynin.
- Antidepressant and antipsychotic agents: These include citalopram, haloperidol, and phenelzine.
- Diuretics: These include furosemide, chlorothiazide, and hydrochlorothiazide.
- Blood pressure medications: These include captopril, lisinopril, and enalapril.
- Sedatives: These include alprazolam, diazepam, and triazolam.
- Muscle relaxants: These include tizanidine, cyclobenzaprine, and orphenadrine.
- Pain medications: These include opioids and NSAIDs.
- Antihistamines: These include first-generation antihistamines such as diphenhydramine, chlorpheniramine, and meclizine.
- Anticholinergic agents: Doctors prescribe anticholinergics for overactive bladder, vomiting, and Parkinson’s disease.
According to a
If none of the above work, doctors can prescribe medications. These include the FDA-approved pilocarpine and cevimeline, which can stimulate salivation.
The same
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.