Cold Sores

Though they’re also called fever blisters, you don’t get cold sores from fevers or colds. Cold sores are usually passed via a kiss, shared utensils, or other close contact. These small, fluid-filled mouth blisters may appear on the lips or just near them. Though they’ll  go away in a few days, most people want to ease their pain. OTC creams and ointments do that and speed healing.  Repeat sores may require a prescription.

Canker Sores

No one knows what causes these small, painful blisters inside your mouth. Triggers include hypersensitivity, infection, hormones, stress, and not getting enough of some vitamins. Also called aphthous ulcers, canker sores can show up on your tongue, cheek, even gums. They usually last a week or two. Persistent, severe canker sores can be treated with numbing creams or prescription treatments.

Thrush

Caused by candida yeast, thrush is most common in older adults or babies. But a weakened immune system, antibiotics, diabetes or certain medications such as  inhaled corticosteroids can give candida a chance to grow wild. Wiping away the patches will cause soreness. See a doctor for a firm diagnosis.

Leukoplakia

Leukoplakia is the mouth’s reaction to an irritant, like rough teeth, badly-fitting dentures, chronic smoking, even sun exposure to the lips. It usually is painless, but may be sensitive to touch or heat. Usually harmless, leukoplakia generally clears up in a few weeks after you remove the irritant. But sometimes leukoplakia can also be a precancerous condition that shows up as white patches or plaques in the mouth.  Persistent patches may need a dentist’s care.

Black Hairy Tongue

This painless condition occurs when the little bumps on your tongue grow long and trap the bacteria that live in your mouth -- making your tongue look black and hairy. There can be lots of causes for black hairy tongue, including antibiotic use, poor oral hygiene, smoking, drinking a lot of tea or coffee, and not producing enough saliva. Brushing your tongue and using a tongue scraper is usually all you need to treat it, though sometimes medication is necessary.

Lichen Planus

A rare rash that shows up as lacy, white patches or red shiny bumps on the inside of the cheeks, but also on the  tongue, could be lichen planus. No one knows what causes it or the resulting inflammation. Generally, mild lichen planus doesn’t need any treatment. If it causes pain or ulcers, it can be treated with oral and topical medication. Oral lichen planus can be chronic and may increase the risk for oral cancer. Lichen planus can also affect skin, scalp, nails, and genitals.

Geographic Tongue

When parts of your tongue are missing some of their small bumps (called papillae), you end up with raised and lowered spots, giving your tongue a map-like appearance. The spots can change location, pattern, and size within minutes to hours. Geographic tongue is harmless and can come and go over time. It usually doesn’t need any treatment. If there’s pain, over-the-counter pain relievers and anti-inflammatory medications can help.

Mouth Cancer

A mouth sore that doesn’t go away for weeks; unexplained numbness in the face, mouth, or neck; problems chewing, speaking or swallowing -- these are a few of the symptoms of mouth cancer. The causes can include smoking cigarettes and using smokeless tobacco, drinking heavily, overexposure to the sun, and a family history of cancer. Don’t let fear keep you from the doctor -- oral cancer that is caught early is treatable and curable.

Gum Disease

Red, swollen, or bleeding gums could be gingivitis, which can cause teeth to loosen and fall out. Also called gum disease, gingivitis – a form of periodontal disease -- can happen when an illness, medication, plaque, or other problem leaves gums vulnerable to bacterial infection. Prevention is the best strategy. That means daily flossing and brushing, as well as regular dental visits. Severe gingivitis may require antibiotics.

Periodontal Disease

With periodontal disease like gingivitis, bacteria in plaque can cause receding gum lines. Pockets form that become infected and can cause bone loss. Proper oral hygiene can help prevent periodontal disease. Smoking, poor diet, and stress can make it worse. See your dentist to treat receding gums.

Taking good care of your teeth and mouth is up to you. For more WebMD tips on oral health care, click “Next.”

Cavities, Abcesses, & Discoloration

Flossing and brushing daily helps prevent teeth problems like cavities, abscesses, and tooth discoloration. Your dentist can spot these problems before they become painful. Don’t mess around with a severe toothache. Dental infections can spread to the face, skull, and even to the bloodstream.See your dentist as soon as possible if your toothache lasts longer than 1 or 2 days or if you have a fever, earache, or pain when you open your mouth wide.

Chipped Teeth

Munching on ice or hard candies, grinding or clenching teeth, even exposing teeth to heat and cold can lead to chips, cracks, and breaks in your teeth. Tiny chips or cracks may not be a bother. But anything more could lead to pain or permanent tooth damage. Your dentist can offer dental bonding, tooth contouring, porcelain veneers, and crowns to fix badly damaged teeth.

Bad Breath

Unbrushed teeth have food particles around them that promote bacteria and cause bad breath. Persistent bad breath or a bad taste in your mouth may be from continuous breathing through your mouth, dry mouth, a sign of gum disease, or even diabetes. Fight bad breath by brushing your teeth and tongue, drinking water, and avoiding food triggers. See your dentist if bad breath persists.

Aspirin Burn

Ever let an aspirin nestle in your cheek, near an aching tooth? While you may hope this relieves  pain faster, instead the acid in the aspirin burns a white, rough lesion into your gums or cheek. Preventing aspirin burn is simple -- swallow those pain relievers! Treatment for aspirin burn is just as basic: Time. Simple burns should heal in about two weeks.

Amalgam Tattoo

Ever notice a small blue-gray “stain” in a soft part of your mouth after dental work? Called amalgam tattoos, they occur when a tiny piece of amalgam filling gets embedded in your cheek or gum. The silver in the amalgam leaches into your mouth’s soft tissue, resulting in what looks a bit like a tiny tattoo. Amalgam tattoos pose no harm. But if the blue-gray spot grows or changes color, that’s not an amalgam tattoo. Ask your dentist to check it out.

TMJ

A problem with the jaw called temporomandibular joint syndrome can cause  severe pain in the jaw, face, ear, or neck. Clenching, tooth grinding, or injury can all cause TMJ, but the results are often the same: pain, headaches, dizziness, even trouble swallowing. Treatment may involve rest, a mouth guard, medication, or surgery.

More Reading on Oral Health

• Guide to Teeth Whitening
• 15 Ways to Freshen Bad Breath
• What Your Dental Health Says About You
• What's New at the Dentist
• Get the Facts About Fluoride
• The Truth About Diet and Oral Health
• Sign Up for WebMD's Daily Newsletter