The tongue is a powerful and important muscle – integral for taste, chewing and processing food, and speech. The oral part of the tongue, 
containing the anterior two-thirds of the tongue, lies mainly in the mouth, while the pharyngeal part of the tongue consists of the posterior third.
The oral part is covered in bumpy papillae, which come in four types. Three of these four types have taste buds on their surfaces. The average human tongue has 2,000 to 8,000 taste buds.
There are five taste sensations – sweet, bitter, salty, sour, and umami, which is often known as meaty or savoury.
The average length of the tongue is 10cm from oropharynx to tip, but the world’s longest tongue belongs to Stephen Taylor, whose extended tongue from tip to lip is a whopping 9.5cm.
The tongue often gets neglected in the pursuit of oral hygiene, but it’s important to make sure your tongue is both healthy and clean.
A tongue should typically be pink and relatively smooth.
A white tongue can indicate an infection present on the tongue, while an overly dark tongue is often the result of diet, lifestyle or medications, such as antibiotics. Bismuth medications, such as Pepto Bismal, can even turn the tongue temporarily black. This dark staining – whether from coffee, cigarettes, or medication, should fade with brushing and time.
A bright or dark red tongue can be the result of nutritional deficiencies, though a temporary red and painful tongue can also be a reaction to something consumed, such as mouthwash, toothpaste, or acidic foods.
A yellow tongue is typically the result of a bacterial or fungal infection, though could also be attributed to gastric reflux.
An abnormally pale and smooth tongue can be a symptom of anemia, or iron deficiency.
If you tongue begins to appear "hairy", this is likely because the filiform papillae on your tongue have become elongated. This can be the result of infection, antibiotics, or a very dry mouth.
Canker sores (or mouth ulcers), which can appear anywhere in the mouth including on the tongue, can result from consuming too much citrus, having a cold of fever, or biting your tongue, and should disappear within approximately 10 days. If your canker sores persist longer however, it is worth seeing a doctor, as they may be a sign of mouth cancer.
Small bumps on the tongue – from inflamed papillae, are also normal, as long as they disappear within a few days. As with canker sores, a prolonged and painful inflammation may signify mouth cancer.
An inflamed tongue can signify an allergic reaction, so it is worth of trip to the doctor if this symptom persists.
Finally, burning mouth syndrome describes a painful, burning sensation that can affect just the tongue or the entire mouth. This condition, which is not particularly well understood, often affects post-menopausal women, though both the causes and solutions are unknown. Drinking water, chewing gum, and taking anti-anxiety and anti-depressant drugs are current treatments that seem to help manage the syndrome.
In order to clean your tongue, you can invest in a tongue brush or scraper, or simply use your toothbrush to brush your tongue. An inverted spoon can also be used. It is recommended to clean your tongue before, not after eating, so the bacteria on your tongue does not get swallowed along with the food and drinks you are consuming.
Tongue cleaning is important for fresh breath, oral hygiene, and general health.
