Has your doctor asked you to stick out your tongue and say "aaah"? While the GP assesses your throat, they're also checking out your tongue, which can reveal a lot about your health.

The doctor will look for any changes in the tongue's surface or how it moves. This can indicate issues in the mouth itself, as well as the state of your overall health and immunity.

But there's no need to wait for a trip to the doctor. Cleaning your tongue twice a day can help you check how your tongue looks and feels – and improve your breath.

What does a healthy tongue look like?

Our tongue plays a crucial role in eating, talking and other vital functions. It is not a single muscle but rather a muscular organ, made up of eight muscle pairs that help it move.

The surface of the tongue is covered by tiny bumps that can be seen and felt, called papillae, giving it a rough surface.

These are sometimes mistaken for taste buds – they're not. Of your 200,000-300,000 papillae, only a small fraction contain taste buds. Adults have up to 10,000 taste buds and they are invisible to the naked eye, concentrated mainly on the tip, sides and back of the tongue.

A healthy tongue is pink although the shade may vary from person to person, ranging from dark to light pink.

A small amount of white coating can be normal. But significant changes or discolouration may indicate a disease or other issues.

How should I clean my tongue?

Cleaning your tongue only takes around 10-15 seconds, but it's is a good way to check in with your health and can easily be incorporated into your teeth brushing routine.

You can clean your tongue by gently scrubbing it with a regular toothbrush. This dislodges any food debris and helps prevent microbes building up on its rough textured surface.

Or you can use a special tongue scraper. These curved instruments are made of metal or plastic, and can be used alone or accompanied by scrubbing with your toothbrush.

Your co-workers will thank you as well – cleaning your tongue can help combat stinky breath. Tongue scrapers are particularly effective at removing the bacteria that commonly causes bad breath, hidden in the tongue's surface.

What's that stuff on my tongue?

So, you're checking your tongue during your twice-daily clean, and you notice something different. Noting these signs is the first step. If you observe any changes and they worry you, you should talk to your GP.

Here's what your tongue might be telling you.

White coating

Developing a white coating on the tongue's surface is one of the most common changes in healthy people. This can happen if you stop brushing or scraping the tongue, even for a few days.

In this case, food debris and microbes have accumulated and caused plaque. Gentle scrubbing or scraping will remove this coating. Removing microbes reduces the risk of chronic infections, which can be transferred to other organs and cause serious illnesses.

Yellow coating

This may indicate oral thrush, a fungal infection that leaves a raw surface when scrubbed.

Oral thrush is common in elderly people who take multiple medications or have diabetes. It can also affect children and young adults after an illness, due to the temporary suppression of the immune system or antibiotic use.

If you have oral thrush, a doctor will usually prescribe a course of anti-fungal medication for at least a month.

Black coating

Smoking or consuming a lot of strong-colored food and drink – such as tea and coffee, or dishes with tumeric – can cause a furry appearance. This is known as a black hairy tongue. It's not hair, but an overgrowth of bacteria which may indicate poor oral hygiene.

Pink patches

Pink patches surrounded by a white border can make your tongue look like a map – this is called "geographic tongue". It's not known what causes this condition, which usually doesn't require treatment.

Pain and inflammation

A red, sore tongue can indicate a range of issues, including:

- Nutritional deficiencies such as folic acid or vitamin B12

- Diseases including pernicious anaemia, Kawasaki disease and scarlet fever

-  Inflammation known as glossitis

- Injury from hot beverages or food

- ulcers, including cold sores and canker sores

- Burning mouth syndrome.

- Dryness

Many medications can cause dry mouth, also called xerostomia. These include antidepressants, anti-psychotics, muscle relaxants, pain killers, antihistamines and diuretics. If your mouth is very dry, it may hurt.

What about cancer?

White or red patches on the tongue that can't be scraped off, are long-standing or growing need to checked out by a dental professional as soon as possible, as do painless ulcers. These are at a higher risk of turning into cancer, compared to other parts of the mouth.

 Oral cancers have low survival rates due to delayed detection – and they are on the rise. So checking your tongue for changes in colour, texture, sore spots or ulcers is critical.