Albert Einstein famously stuck out his tongue and Chinese medicine practitioners read it for clues to inner health. The tongue -- that undulating muscle covered with pointy papillae and 10,000 taste buds that sense sweet, salty, sour and bitter -- has on its surface thousands of bacteria, some pro (as in “probiotics”) and some con (as in “make your breath so bad you can't have a CONversation”).

When everything is OK, the tongue is pinkish and sits comfortably in your mouth. Chances are you rarely think about it unless you're cleaning it (you do, don't you?) when you brush your teeth. Use a tongue scraper or toothbrush to remove plaque and bacteria and keep breath fresh.

Sometimes, however, the tongue changes. Three disorders -- with no serious health consequences but lots of ick factor -- include black-hairy, yellow and geographic tongue. (Geographic tongue causes smooth red patches with raised edges.) These conditions may be from bacterial overgrowth, an immune system glitch or an allergy.

Other tongue problems? Small ulcers on the edges of the tongue pop up from stress; lesions (raised, smooth, white areas) could indicate oral cancer; and thrush (a yeast infection) turns the tongue white.

Solutions? Antibiotics or other medications may be needed, but first try saltwater rinses along with brushing and flossing a lot. Stop using mouthwash or toothpaste with peroxide or with astringents such as menthol, and don't smoke! If symptoms (especially a hard and white lesion) stay for 10 days, see your dentist or ENT (otolaryngologist). It may save your life.

Mehmet Oz, M.D. is host of “The Dr. Oz Show,” and Mike Roizen, M.D. is Chief Medical Officer at the Cleveland Clinic Wellness Institute. For more information go to www.RealAge.com.