Saliva is among the most under-appreciated body fluids and yet it plays major roles in the body, including helping protect teeth from decay, preventing infection and making chewing and swallowing possible. It is also a key ingredient for breaking down food in the mouth and enabling proper digestion, as well as washing away food remnants and debris afterward.

Dr. Stuart Froum, president of the American Academy of Periodontists, says: “If the eye is the window to the soul, the mouth is the window to the body.” Saliva in the mouth is one of the best indicators of health. If something is off, there is a good chance your saliva will change as a direct reflection. Here are some key things your saliva can tell you about your health you should pay more attention to.

1. You’re taking the wrong (or too many) prescription and over-the-counter medications.

Saliva is produced around the clock and is affected not only by every bite of food you take, but also every other thing you put in your mouth. If you notice your saliva is too stringy or thick, your body might be having a hard time producing saliva. This could be because of the prescription and over-the-counter medication you are taking. Prescription and over-the-counter medications like cold and allergy pills can alter the amount of water flow in and out of cells and lead to gum disease and tooth decay if not addressed.

2. You’re nervous, anxious or stressed out.

When you are nervous, anxious, upset or under a lot of stress, you are susceptible to dry mouth. Dry mouth, clinically known as xerostomia, is when you don’t have enough saliva in your mouth. This condition can be very uncomfortable and result in difficulties in tasting, chewing, swallowing and speaking. If you find you have dry mouth too often, it could be your cue right there to relax and stop worrying too much.

3. You’re iron-deficient.

Stand in front of the mirror and stick out your tongue. If your tongue is a pale color and you have dry mouth, there is a good chance you have critical iron deficiency or iron-deficiency anemia. Iron helps maintain your immune system and gives you the energy you need to carry out day-to-day activities. Without enough iron, your body can’t make hemoglobin—the pigment in red blood cells that gives your tongue its healthy, pink-red color. Eat iron-rich foods to replenish the iron your body needs, such as beans, lentils, meat, seafood and dark green leafy vegetables like spinach, kale and chard.

4. You’re emotionally sensitive.

Studies indicate that an imbalance of the ‘stress hormone’ cortisol in saliva points to emotional sensitivity to stressful situations. Cortisol is known as ‘the stress hormone’ because stress activates cortisol secretion. Interestingly, researchers have also discovered that if a female’s saliva contains lower-than-normal levels of cortisol in the morning and high levels of the stress hormone when she discusses problems or stressful events with friends, chances are high she doesn’t have a strong relationship with her father! That discovery might be a little hard to swallow, but the measurement of cortisol in saliva is becoming increasingly acceptable as a screening test for hypercortisolism, such as depression, hypertension and diabetes.

5. You may have salivary stones.

Saliva contains significant amounts of calcium. If saliva builds up in the salivary ducts (tubes where saliva passes), pale, crystallized mineral rocks can form in the same manner kidney stones form. Schedule an evaluation with the doctor if you are having trouble swallowing, have pain or swelling in your neck and a dry mouth constantly. That is a sign you might have a salivary stone, clinically referred to as sialolithiasis.

Take away:

Pay more attention to issues in your mouth and report anything concerning about your saliva to a qualified doctor. Doing so can not only help treat the issues in your mouth, but also make it easier to identify and treat conditions that affect other parts of the body. Doctors are well equipped with different strategies to treat mouth and saliva problems, including recommending sprays and saliva substitutes.