A tour of your mouth can provide clues to your overall health.

Let’s take a tour around the inside of your mouth. With just a few minutes of exploring your teeth, gums, tongue, and lips — as well as the lining of your cheeks — you could learn something important about your health. Here’s what you should look for:

-Stick out your tongue. Symptoms of low iron, a sluggish thyroid, or a fungal infection like thrush can show up here. If you have low iron, your tongue might look a little inflamed. A sluggish thyroid may cause your tongue to thicken. And a fungal infection can show up as white patches on your tongue. Look for lumps, ulcers, bleeding, and sores, too. They could indicate something mild — like a viral infection — or something much rarer but serious, like tongue cancer.

-Check your cheeks. Look at the mucous membrane lining your mouth and the inside of your lips for signs of irritation, which can appear as white or gray patches (called leukoplakia) or red patches (called erythroplakia). Irritation in and of itself may not be harmful. But it could indicate anything from a rough tooth or filling that’s rubbing against your cheek to something more serious, such as a precancerous lesion. Also, don’t ignore canker sores. These small, shallow ulcers are usually harmless but can be painful. And if one persists for more than 10 days or returns frequently, it may signal a vitamin deficiency, a bacterial infection, or even an inflammatory bowel disease.

-Look at your lips. Got a tingling, itchy red spot coming on? If it’s a cold sore (also known as a fever blister), you’ll want to treat it fast. Medications are now available that speed healing of these painful fluid-filled blisters, but treating them early produces the best result. Start treatment at the first sign of a cold sore. Typically, once the blister breaks, a crust will form that lasts about a week.

-Scan your gums. Puffy, red, inflamed gums can signal any number of things. You may simply be brushing too hard or using a toothbrush with too-stiff bristles. Or you may be flossing improperly and irritating your gums. But, typically, red and inflamed gums are a classic sign of gingivitis, the first step toward periodontal disease. Time for a checkup.

Let a Pro Take a Peek

Of course, you shouldn’t count on your own eyes to determine whether your mouth is showing signs of disease. And you don’t want to wait for an obvious problem before you see a medical professional. So see your dentist twice a year for a thorough exam — one that includes peering into every nook and cranny of your mouth. And if you’ve noticed anything odd in there, bring it up. But trouble may be brewing long before you notice it — and can occur in places where you can’t see — so you need to call in the experts for a look, too.

This article originally appeared on Sharecare.com, the leading online health and wellness social platform.