What Your Saliva Tells You About Your Health
Did you know your body makes up to 7.5 cups of saliva every day? You likely don’t notice or think much about your spit, but it plays a key role in your oral health. Too much or too little can be a sign of certain illnesses, especially those affecting your mouth or throat. Saliva also contains proteins, enzymes, hormones and other markers for many diseases and genetic conditions. Increasingly, saliva tests are being used instead of blood tests to help identify health issues.
To understand why saliva can clue you in on your oral health, it’s helpful first to understand how saliva functions.
Saliva is made by your salivary glands, located in your mouth and at the back of your throat. It’s composed almost entirely of water (98 to 99%), with a little bit of protein and salts. Your salivary glands cut back on production when you’re asleep, but flood in more when you’re ready to sit down to a meal—sometimes even when you just start thinking about food.
Other saliva functions include:
- Aiding digestion through enzymes in saliva that help break down food
- Enhancing your ability to taste food
- Preventing tooth decay by neutralizing acids and bacteria, remineralizing your teeth, and washing away food particles
Saliva can vary in amount, color and consistency. By examining your saliva, you can get clues to health problems you may have. Some of these signs include:
- Too little saliva. Dry mouth (xerostomia) can be caused by medications or medical treatments like chemotherapy or radiation, as well as illnesses like anemia, Sjogren’s syndrome and hypertension. Stress can also leave you dry-mouthed, though usually this is temporary. Left untreated, lack of salivation can lead to tooth decay and gum disease. If you have dry mouth, tell your dentist. Treatments include special oral rinses or hydrating gels.
- Too much saliva (hypersalivation). This can indicate several conditions: pregnancy, a mouth infection, acid reflux, or neuromuscular diseases, such as Parkinson’s disease or stroke. If you notice you are producing more saliva than normal, tell your dentist.
- Bloody spit. If your gums bleed after brushing, this can be a sign you have developed gingivitis or periodontitis. If bleeding persists, you should contact your dentist or a periodontist. Bleeding and inflammation in your gums should not be ignored, because this could indicate the presence of bacteria, which can be linked to inflammation in heart vessels and infection in heart valves.
- Spit that is white and gooey. Saliva should be clear and thin. If yours is white and thicker than normal, you could have a yeast infection called thrush or candidiasis. This condition may appear as white patches on your mouth and tongue. Tell your dentist or doctor about this right away.
- Bitter-tasting saliva. If you have a persistent sour or acidic taste in your mouth despite good oral hygiene, you could have stomach acid backing up in your throat. If this continues, you should bring it to your doctor’s attention. Gastroesophageal reflux, or GERD, not only can cause painful heartburn but can damage your esophagus—potentially even causing cancer—if left untreated.
Besides these visual cues, a variety of saliva tests can also help your doctor diagnose health issues. One type, called sialometry, measures how much saliva you make in a given time period. Other “spit in the tube” tests examine what’s in your saliva to identify if you have cavities or periodontal disease. Trade names for these include MyPerioPath and MyPerioID.
Other saliva tests can check for the presence of systemic inflammation, SARS-CoV-2 (the virus that causes COVID-19), AIDS, cystic fibrosis, arthritis, and signs of heart problems, among other conditions. One test, OraRisk HPV, detects the presence of the human papillomavirus (HPV), which can be a marker for oral cancer. Researchers are developing saliva tests that can detect high cholesterol and be used by diabetics to monitor blood sugar levels.
Some conditions can affect your salivary glands, interfering with salivation or creating other problems that need dental attention, including:
- Salivary stones (sialolithiasis). These “stones” are hardened mineral deposits that form in your salivary glands. They are most common in those ages 30 to 60 and are more common in men than women. They may be caused by dehydration, inner-mouth trauma, smoking and gum disease. They can be painful, but most often go away by applying moist heat, gentle massage, and by keeping well-hydrated. You can also take medication such as ibuprofen to help relieve pain and swelling. Stones that are especially large or irregularly shaped may need surgical removal.
- Infected salivary gland (sialadenitis). Sometimes a salivary gland’s duct becomes blocked by a salivary stone, resulting in infection. Your dentist may prescribe antibiotics if this occurs.
- Inflammation of the salivary glands (sialosis or sialadenosis). Sometimes major salivary glands—usually the parotids, located at the back of your throat—become inflamed and swollen. Some people experience pain with this condition, which can be associated with malnutrition, obesity, diabetes, alcoholism, liver disease, certain drugs (such as antihypertensives), or eating disorders. Bulimics who purge via self-induced vomiting may wind up with inflamed parotid glands, resulting in swollen “chipmunk cheeks” that don’t return to normal until several weeks after purging ends. Medication also can help relieve sialosis.
Whether you notice a condition in your salivary glands or within your spit, it’s important to keep a vigilant eye on what’s happening in your mouth and to notify your dentist or doctor if you see anything of concern.