Have you ever had a small, annoying sore in your mouth? It’s not fun – a little spot with a white or yellow center and a red border. They can be a pain, making eating, drinking, talking and brushing your teeth a bit of a hassle.

They’re mouth ulcers, also known as aphthous ulcers or canker sores
and typically occur on the inner cheeks, inner lips, base of your
gums or roof of your mouth. They can also appear on your tongue.

Thankfully, "mouth ulcers generally clear up by themselves within
seven to 10 days," says Dr. Christoph Benz, president of the German
Dental Association (BZÄK).

At least this is the case with minor ones, the most common type,
which have a diameter of 2 to 3 millimeters – and rarely as large as
10 millimeters. They heal without scarring.

Major mouth ulcers, on the other hand, can have a diameter of 3
centimeters and are extremely painful. They take several weeks to
heal and often leave scarring.

A third type, herpetiform mouth sores (not caused by herpes virus
infection), are uncommon. Pinpoint in size, they occur throughout the
mouth in clusters of up to 100 and heal within seven to 10 days
without scarring.

What causes mouth ulcers?

The exact causes haven’t yet been conclusively determined, according
to Benz. "Under discussion as possible triggers are injuries to the
oral mucosa from toothbrushes or a vitamin deficiency, for instance,"
he says, adding that allergic reactions or stress could cause them, too.

Mouth ulcers are made more likely by pressure marks from dentures or
braces and also fillings with sharp edges, notes Dr Ursula
Sellerberg, deputy spokesperson for the Federal Union of German
Associations of Pharmacists (ABDA).

They’re more common in girls and women than boys or men and younger people
than older ones. "The reasons for this are also unclear as yet," Benz
says.

What to do if you have a mouth ulcer?

First of all, you can try to reduce inflammation with a mouthwash,
for example, one containing highly dosed camomile extract. Mouthwashes
with alcoholic camomile extracts, as well as a camomile infusion (10
grams of camomile flowers steeped in 100 milliliters of boiled water),
are anti-inflammatory, says Sellerberg.

She says they hardly alleviate the burning sensation or pain, though,
and "normal camomile tea is dosed too low to have any real effect."

What does help, however, are gels, pastes, ointments, sprays or
tablets that are available in pharmacies. Before you apply a gel,
paste or ointment, dab the mouth ulcer dry with a cotton bud, as,
"This will prolong the time the medication remains on the
mucosa," Sellerberg recommends.

Painkilling medications are best taken before meals so that the pain
while chewing is tolerable.

All other medications should be used after eating and toothbrushing.
"You shouldn’t drink anything for 30 minutes afterward," says
Sellerberg; otherwise, the medication will be washed away and have
little effect.

If symptoms are severe, a corticosteroid preparation can help. Before
using it for the first time, you should consult a doctor.

When should you see a doctor?

If your self-care measures bring no improvement within 14 days, it’s
time to see a dentist. Seeing a doctor is also advisable if you get
mouth ulcers more than three times a year.

You should also see a GP, dermatologist or ENT physician if aphthous
ulcers appear elsewhere on your body, which is possible, or if your
symptoms include fever, swollen lymph glands or gastrointestinal
problems, for example, which can be symptoms of certain illnesses.

"It could be a condition that affects the digestive system, such as
Crohn’s or coeliac disease," Benz says. Or perhaps your body
has too few white blood cells. It’s also conceivable that leukemia
or an infectious disease such as HIV/AIDS is behind mouth ulcers.

Taking certain medications, such as corticosteroids, can cause them
, too, as can deficiencies of vitamin B12 or iron, for instance.

Can you prevent mouth ulcers?

"This is difficult since the causes aren’t quite clear," says Benz.

What nevertheless helps, says Sellerberg, is to "reduce stress and
maintain a healthy lifestyle – with a balanced diet, plenty of
exercise, no nicotine, little alcohol and sufficient sleep."

If necessary, you should also get ill-fitting dentures or braces
fixed. And proper oral hygiene is always important, of course.