A sore or painful tongue is usually caused by something obvious and visible, although there are a few less obvious causes you should be aware of that may need treating.

If the pain is persistent and you haven't accidentally bitten or burnt your tongue, see your GP or dentist. There may be an underlying problem that needs treating, and your GP or dentist may be able to advise you about pain relief while you wait for it to get better.

This page outlines the most likely causes of tongue pain, but you shouldn't use it to diagnose yourself with a condition – always leave that to a healthcare professional.

Common causes

Common causes of tongue pain are outlined below.

Geographic tongue

Also known as benign migratory glossitis or oral erythema migrans, geographic tongue is a common condition that causes irregular red patches surrounded by white lines to develop on the tongue, giving it a map-like appearance. In some people, the red patches may feel sore or sensitive to certain foods and drinks.

You may notice that after a few days, weeks or months the position of these lines and patches change. They may disappear and re-appear later on a different part of the tongue.

Some people find the condition improves over time, while for others it may be persistent. See your GP or dentist if you have persistent discoloured or painful patches on your tongue.

It’s not clear exactly what causes geographic tongue and there is no specific treatment for it, but you may be able to manage the pain by taking over-the-counter painkillers (speak to your pharmacist for advice) and avoiding anything that makes it worse, such as acidic, spicy or hot foods.

Oral thrush

Oral thrush is an infection in the mouth caused by a fungus, which can cause a coated or white tongue and areas of soreness.

You are more likely to develop oral thrush if you:

• have recently taken antibiotics
• have poor oral hygiene
• wear dentures (false teeth), particularly if they don't fit properly
• have a weakened immune system
• have diabetes

You should see your GP if you think you have oral thrush. If it is left untreated, the symptoms will persist and your mouth will continue to be uncomfortable.

Oral thrush is treated with antifungal medicines taken for around a week. These usually come in the form of gels or liquid that you apply directly inside your mouth, although tablets or capsules are sometimes used.

Aphthous mouth ulcers

Aphthous mouth ulcers are painful sores that can occur anywhere within the mouth and are common on the underside of the tongue.

Many mouth ulcers are caused by damage to the mouth, such as from accidentally biting your tongue or eating something hard and sharp.

Ulcers that keep recurring have been linked to things such as stress, anxiety, hormone changes, certain foods and stopping smoking. Read more about the causes of mouth ulcers.

Most mouth ulcers heal within a week or two and you may be able to manage the pain in the meantime by taking over-the-counter painkillers and avoiding anything that worsens it, such as spicy foods.

See your GP or dentist if you have an ulcer that doesn’t improve within a few weeks or if you develop ulcers regularly.

Less common causes

Less commonly, tongue pain may be caused by:

• a viral infection – such as an infection by viruses that cause hand, foot and mouth disease or cold sores
• vitamin deficiencies and anaemia – a sore tongue can sometimes be a symptom of iron deficiency anaemia and vitamin B12 or folate deficiency anaemia
• median rhomboid glossitis – where a smooth, red, inflamed patch develops on the middle or back of the tongue, thought to result from a fungal infection
• glossodynia or "burning mouth syndrome" – a burning pain on the tip of the tongue that is often seen in people with depression
• glossopharyngeal neuralgia – repeated episodes of severe tongue pain believed to be caused by nerve irritation
• lichen planus – a long-term skin condition that causes an itchy rash and can also affect the mouth, causing a white lacy pattern and painful patches on the tongue
• Behçet's disease – a rare condition that causes inflammation of the blood vessels and can also lead to painful mouth ulcers 
• pemphigus vulgaris – a rare and serious condition that causes painful blisters to develop on the skin, as well as inside the mouth, nose, throat, anus and genitals
• medications – painful mouth ulcers can be a side effect of non-steroidal anti-inflammatory drugs (NSAIDs) and beta-blockers, and certain mouthwashes can cause tongue pain in some people
• Moeller's glossitis – a type of inflammation of the tongue
• cancer of the tongue – although this is rare

Click on the above links for more information about these conditions and medications.