Having a canker sore on the tongue can be extremely annoying and interfere with the ability to eat and drink, and in some cases it’s so painful it even makes it hard to talk. In fact, it is arguably the worst, most painful place to have a canker sore.
Symptoms
Canker sores are a non-contagious kind of mouth ulcer that can develop on the inner lip and inside cheeks, gums, soft palate, as well as on the tongue. They are usually small, round or oval, white or grayish with a red border. They can look like pimples on the tongue. Although small, usually less than 12mm, they can pack a wallop of pain. Sores usually heal in about a week or 10 days, and although they can drive you crazy they are generally harmless. Canker sores are not the same as cold sores, which are only on the outside of the mouth and are caused by a virus.
Causes
Although the precise cause is unknown, there are a number of factors that can trigger these painful ulcers. Typical culprits include stress, eating or drinking acidic foods like tomatoes and pineapple, food allergies, particularly to chocolate, nuts, dairy and eggs, hormones, and sometimes nutritional deficiencies including lower than optimum levels of B-12, folic acid or iron. It can even be caused by accidentally biting your tongue. Canker sores afflict about 10% of the population at any given time, woman more often than men, and as many as 30-40% of people with recurrent mouth ulcers find it runs in their family.
How to Treat Cancer Sores
If you have a canker sore on your tongue in particular, all you want is for it to go away. They can be extra painful in this location and healing generally won’t happen overnight. However, there are a few simple home remedies you can try to make it less painful.
Aloe Vera Juice
Some folks swear by aloe vera juice. Although it tastes bitter, it can be an effective treatment for some people. Just dab a little juice or gel, either from a fresh leaf or from a health food store, directly on the ulcer. You’ll need to do this multiple times a day because of course it’s hard to get anything to stick on your tongue.
Mouth Rinse
For canker sores on the tongue, probably the best solution for easy application is a mouth rinse. You can make an easy one by combining half water and half hydrogen peroxide and swishing it around in your mouth 3-4 times per day. A popular product called Gly-oxide Antiseptic Oral Cleanser 
Tannin from Black Tea Bag
Another easy remedy to try at home is tannin, which can be found in black tea. Just place a wet teabag on your tongue and keep it there for at least five minutes. The properties found in the tannin help anesthetize the sore.
Milk of Magnesia
This remedy may not be the first thing that comes to mind, but it gets surprising support from doctors and dentists. Mix equal parts of Milk of Magnesia
Salt Water
Swishing warm salt water around in your mouth may help relieve the pain.
Food and Drink: Bland is Best
When you have a canker sore on the tongue, it is best to avoid acidic food and beverages, nuts, seeds, coffee, alcohol and tobacco products. Eat bland foods including yogurt and cut your food in small pieces or mash it.
Careful When Brushing
Take care when you brush your teeth. Brush gently but thoroughly. Brushing too briskly could result in canker sores developing. Use a toothpaste that doesn’t contain sodium laurel sulfate (SLS), which is a foaming agent found in most brands of toothpaste. It has been found to be an irritant for some people and may make canker sores worse. There are several SLS-free toothpastes available, including Biotene 
Caution
If within 2-3 weeks your canker sore on the tongue or elsewhere hasn’t healed, has gotten worse or grown in size, you should check with your doctor. While canker sores are benign, you should get the sore evaluated to make sure you do not have an underlying condition. Canker sores are not cancer, but squamous cell cancers may appear as an ulcer that does not heal.