Saliva is the key ingredient in food digestion, and helps protect teeth from decay, prevents infection, and makes chewing and swallowing possible. Without saliva we wouldn’t be able to break down food for proper digestion or wash away food and debris afterward.

Saliva is one of the best indicators of health, as it maintains balance in the body, so if something is off there’s a good chance your saliva has changed as a direct reflection. Spit screening can expose an array of biological secrets to doctors with just half of an eyedropper worth of spit. By just screening for a specific protein, doctors have the ability to assess heart disease risk.

When you’re stressed, salivary glands secrete an enzyme into the mouth known as salivary alpha-amylase and doctors can use it to gauge the amount of stress a mother places on her unborn babe. Conversely, if a female’s saliva contains abnormally low cortisol levels in the morning and high levels whenever she discusses stressful events or anxieties, there’s a good chance she doesn’t have a strong relationship with her father. Researchers found the imbalance of cortisol, the stress hormone, indicates emotional sensitivity to stressful situations.

Not only does it harbor 72 different types of bacteria, it’s also one of the most powerful painkillers thanks to the opiorphin it contains. Opiorphin is six times stronger than morphine and helps stop enkephalin pain signals from reaching the brain when the body undergoes an extreme amount of pain to maintain balance, according to the journal of Nature. Saliva is produced around the clock and is affected from every bite of food you take, to every stressful situation you find yourself in. There’s a lot saliva can tell about a person’s health, especially since the salivary glands produce two to four pints of it every day.

Dry mouth, also known as xerostomia, is when you don’t have enough saliva in your mouth, which everyone experiences from time to time. It’ll usually happen if you’re nervous, upset, or under a lot of stress. If you have dry mouth constantly, it can be very uncomfortable and cause difficulties in tasting, chewing, swallowing, and speaking.

A constant dry mouth can be an indication of some serious health problems or disease. If your saliva is thick or stringy, your body might be having a hard time producing saliva, which could be because of prescription and over-the-counter medications, including allergy, pain, and cold meds. They change the amount of water flow in and out of cells, and if left untreated, it can lead to tooth decay, gum disease, and oral yeast infections.

If you have pain or swelling in your neck and trouble swallowing in addition to dry mouth, you may have a salivary stone, also known as sialolithiasis. Saliva is full of calcium, and if it builds up in the salivary ducts, pale, crystallized rocks will form much like kidney stones.

Watch out for bright red and puffy gums, it’s one of the first signs of a bacterial infection or gum disease. Gum disease also indicates diabetes because of the high levels of glucose that accompany high blood sugar levels. Gum disease also increases levels of biological fluids that can induce labor if you’re pregnant. According to the American Academy of Periodontology, gum disease makes pregnant women seven times more likely to deliver their baby prematurely.

That’s not all your saliva can tell you about your health. Stick out your tongue and look in the mirror. If your tongue is a pale color, there’s a good chance you have iron-deficiency anemia, which affects one in five women. We get iron from leafy green vegetables, meat, seafood, and beans. Iron gives you energy and helps maintain your immune system. Without enough, your body can’t make hemoglobin, the pigment in red blood cells that give your tongue a pretty pink-red color.