Saliva plays a critical part in the first steps of digestion by breaking down and softening your food. Sometimes, health conditions, environmental factors, or medications can affect the production and consistency of your saliva, making it uncomfortably thick or creating postnasal drip (mucus) at the back of your throat.

When saliva isn’t thin enough, your mouth becomes too dry, putting you at a higher risk for gum disease and tooth decay.

Thick saliva is a possible symptom of a number of different medical conditions, which range in severity from mild to severe. Some causes include:

Radiation

People who receive radiation therapy around their neck and head may experience thickening of their saliva to varying degrees. Radiation treatment can irritate the salivary glands, causing them to slow saliva production. As a result, your saliva may become tacky or thick.

Dry mouth syndrome

When the salivary glands in your mouth don’t produce enough saliva, it can make your mouth feel parched or dry. A symptom of dry mouth syndrome is stringy or thick saliva, as there is not enough moisture in the mouth to thin it.

Dehydration

If your body loses more fluid than it’s taking in, you can become dehydrated. Dry mouth is one symptom of dehydration, and your saliva may thicken in response to the lack of fluids in your body.

Postnasal drip (mucus)

Your throat and nose produce mucus to filter foreign matter, keep nasal membranes moist, and fight infection. But sometimes, your body produces excess mucus, particularly if you catch a cold or have seasonal allergies.

When you have postnasal drip or a stuffy nose, it can cause you to breathe through your mouth, which then causes your mouth to dry out and your saliva to thicken.

Medication side effects

There are multiple medications, both prescription and over-the-counter, that can cause thick saliva.

These can include:

  • decongestants
  • antihistamines
  • medication for anxiety and depression
  • blood pressure medication
  • pain medication
  • muscle relaxers
  • chemotherapy drugs

Pregnancy

The hormone changes that happen during pregnancy can cause you to develop thicker saliva. Some women even experience hyper salivation or sialorrhea.

Salivary duct stones

Masses of crystallized minerals sometimes form in your salivary glands. This can inhibit saliva production and thicken the saliva that is produced.

Motor neuron disease

Progressive, terminal motor neuron diseases such as ALS (Lou Gehrig’s Disease) can cause problems with thick saliva and excessive mucus. People with motor neuron diseases may experience difficulty swallowing or clearing the airways of the mucus and saliva that builds up due to their illness.

If a person with a motor neuron disease becomes dehydrated, breathes through their mouth, or tends to keep the mouth open, this can make the problem worse. Motor neuron disease is a rare cause of thick saliva.

Salivary gland disorders

Diseases like cancer or Sjogren syndrome can affect your salivary glands and can cause dry mouth or obstructed salivary ducts, which leads to thick saliva.

Cystic fibrosis

Cystic fibrosis is a genetic condition that alters the production of mucus, sweat, and digestive enzymes in the cells.

Fluids like saliva, which should normally be thin and slick, become thick and sticky as a result of the genetic defect, clogging passages throughout the body.

There are multiple ways to treat thick saliva; how you treat your condition depends on the cause. For some people, it will be a simple as identifying and treating the underlying condition under a doctor’s supervision.

General treatments for dry mouth include:

  • changing medication (consult your doctor if dry mouth is a side effect of your medication)
  • brushing and flossing twice daily
  • using prescription saliva substitutes from your dentist or doctor
  • avoiding tobacco, caffeine, abrasive mouth rinse, alcohol, soft drinks, spicy foods, orange juice, and coffee
  • removing partial or full dentures before you go to sleep at night
  • using over-the-counter treatments for dry mouth (e.g., rinses, gels, and toothpastes)
  • taking over-the-counter saliva substitutes
  • eating chewy foods, sucking on sugarless hard candies, or chewing gum to stimulate salivary gland function
  • drinking 8 to 10 glasses of fluid every day (but sip slowly and often to avoid washing away the saliva you do have)
  • sucking on ice cubes
  • using a humidifier in your bedroom when you sleep
  • avoiding hard or crunchy foods that could dry out or cut the inside of your mouth
  • chewing thoroughly before you swallow
  • reducing or eliminating sugar consumption and limiting your salt intake
  • consulting your doctor for dietary recommendations, including information about drinks and foods that could make your condition worse
  • having surgery to open blocked salivary glands

Additional recommendations for people experiencing thick saliva due to radiation or chemo include:

  • eating as many soft or pureed foods as possible and avoiding sticky foods like peanut butter (or any other food that sticks to the teeth or the roof of the mouth)
  • cleaning your mouth thoroughly before and after every meal with mouth rinse or water
  • consulting your doctor about using liquid meal replacements to get adequate nutrition, as well as avoid drying out your mouth

People who are experiencing thick saliva should consult their general practitioner to begin the process of pinpointing the root cause. If you have thick saliva and know your underlying condition, it will be important to know what symptoms are red flags.

You could have an infection in your salivary gland if you’re experiencing:

  • an unusual or bad taste in your mouth
  • high fever
  • more dryness in your mouth than usual
  • intense pain that lasts more than four hours
  • difficulty opening your mouth
  • pain or pressure when eating
  • redness or swelling in your neck and face

If you have postnasal drip along with thick saliva, contact your doctor if you have:

  • fever
  • wheezing
  • green, yellow, or bloody mucus
  • mucus with a strong odor

If you’re dehydrated, you may require immediate, emergency medical attention. Symptoms of dehydration include:

  • lack of sweat production
  • excessive thirst
  • rapid breathing
  • rapid heart rate
  • low blood pressure
  • fever
  • dark urine
  • sunken eyes
  • shriveled skin