Alice Boghosian’s patient was mystifying. Her dental hygiene “was impeccable, she came in frequently for cleanings, she was doing everything right,” recalls Boghosian, DDS, a dentist in suburban Chicago and a spokesperson for the American Dental Association.

But the woman’s gums were unnaturally red — “almost magenta,” Boghosian says — and they bled. “There was nothing I could do for her dentally, so I suggested she see her doctor.”

The patient was diagnosed with autoimmune hepatitis, a chronic disease in which the immune system mistakenly attacks healthy liver cells. “She got the proper treatment and when I next saw her, her gums were healthy,” says Boghosian. “As her dentist, I couldn’t diagnose her liver disease but her gums told me something wasn’t right.”

Related: 6 Surprising Ways to Brush Your Teeth Better

Gum color is just one clue to overall health that you — and your dentist — can pick up on. Here are five other ways your mouth could be saying all is not well.

1. Inflamed or bleeding gums

These are classic signs of gum, or periodontal, disease, which is caused by a build-up of bacteria-laced plaque. On teeth this leads to cavities. On gums it can cause infection.

Periodontal disease can have far-reaching consequences. Studies suggest mouth bacteria can produce toxins that travel through the body and help build another form of plaque, the type made up largely of fatty material that sticks to the arteries. Gum disease has been linked to heart disease, stroke and diabetes, as well as increased risk of premature birth and low birth weight in pregnant women.

People who already have diabetes are more susceptible to gum disease. Treating it provides a bonus, says Boghosian: a healthy mouth and better blood sugar control.

Related: Warning: You Might Have Diabetes and Not Know It

2. Bad breath

Liverwurst and onion for lunch? White garlic pizza for dinner? You know they’re going to linger on your breath. But bad breath that doesn’t fade is “always a red flag,” says Boghosian. While it’s often a symptom of poor dental hygiene or gum disease, persistent halitosis can also signal more than a dozen diseases, from diabetes to cancer.

“A fruity odor is a symptom of abnormal blood sugar,” says Boghosian. An ammonia-like scent may be an early clue to kidney failure.

Scientists are now using a breathalyzer-type instrument to identify and detect compounds associated with various conditions, including lung cancer and heart failure. If you have persistently smelly breath, see your doctor.

Related: 7 Ways to Prevent and Treat Bad Breath

3. Tongue irregularities

A healthy tongue is pink and covered with tiny nodules called papillae. If you say “ahh” and your tongue is bright red, white, black, covered with white patches (they may also appear in other places in your mouth) or is striped, see your doctor.

Most conditions that cause your tongue to morph are benign or easily treated. For example, a black tongue, often called black hairy tongue, is caused by bacterial overgrowth and may simply mean you’re not brushing and flossing often enough. (It can also be caused by use of bismuth salicylate (Pepto-Bismol). A red tongue may be a clue to a vitamin B deficiency.

Cause for alarm: striped tongue, or white patches on the tongue, gums or inside the cheeks. A striped tongue may be caused by oral lichen planus, a chronic inflammatory condition linked to cancer. Thick white patches may be leukoplakia. “This is very common in smokers and is caused by excess cell growth,” says Boghosian. Leukoplakia has also been linked to oral cancer.

4. Tooth erosion

If your tooth enamel is wearing away, you may have gastroesophageal reflux disease, or GERD. Stomach acid is backing up into your mouth, possibly when you sleep, stripping the enamel off your teeth. Nighttime GERD usually needs to be treated aggressively with medication because it’s also linked to other complications, such as chronic cough, wheezing and exacerbation of bronchial asthma.

5. Cracked or worn teeth

“When I see this I always ask my patient, ‘Feeling a little stressed right now?’” says Boghosian. “Stress can cause you to grind your teeth, especially at night. It can take the enamel right off and you can actually create cracks in teeth. I know because it’s happened to me.”

Teeth grinding, or bruxism, can also cause or worsen the jaw pain known as temporomandibular joint disorder (TMJ). The usual remedy: Stress relief techniques such as meditation or deep breathing exercises, or a special bite guard your dentist can make to protect your teeth at night. 

Denise Foley is a veteran health writer and a former contributing executive editor at Prevention magazine.