Why do i have sores inside my mouth

Mouth ulcers, also known as aphthous ulcers or canker sores, are a type of sore that occurs on the inside of your mouth. They can feel uncomfortable, especially when you are talking, eating, drinking and brushing your teeth. In most cases, mouth ulcers are not dangerous and heal on their own. Around 1 in 5 people experience recurrent mouth ulcers.

What do mouth ulcers look like?

Mouth ulcers look like a shallow sore with a white/grey top and a red rim. They can occur as a single ulcer or in a cluster.

Mouth ulcers can appear in different locations around the mouth. Common locations include:

  • inside the lips
  • inside the cheeks
  • on the bottom of the mouth or the gums
  • on the tongue

Why do i have sores inside my mouth
Mouth ulcers look like a shallow sore with a white/grey top and a red rim.

What causes mouth ulcers?

No one knows the exact cause of mouth ulcers, but there are several factors that can make you more likely to develop them.

Mouth ulcers may be caused or triggered by:

About 1 in 3 people who get mouth ulcers have family members who also get them.

When should I see my doctor?

You should see your GP if you think you might have an ulcer related to a mouth infection or disease.

Most mouth ulcers will heal by themselves within a week or two. If your mouth ulcers last longer than this or they keep coming back, see your doctor, as they may be a sign of a more serious problem.

Also, see your GP if you or your child develops severe mouth ulcers with symptoms of general illness such as:

  • weight loss, stomach pain, unexplained fevers
  • mucus or blood in their stool (poo)
  • neck stiffness and tiredness
  • ulcers around the anus

This may indicate a health condition such as coeliac disease or inflammatory bowel disease.

How are mouth ulcers diagnosed?

Your doctor can usually diagnose a mouth ulcer by simply looking at it.

Your doctor may also ask you questions about your symptoms, diet, medical history and what medicines you regularly take.

If your doctor thinks that your mouth ulcer is infected, they may swab the ulcer to confirm an infection and help determine the right treatment.

How are mouth ulcers treated?

Most of the time, mouth ulcers heal on their own without treatment within a week. You can relieve any discomfort with a numbing anaesthetic mouth gel applied to the area, which you can buy over-the-counter from pharmacies.

If you are experiencing a lot of pain from your mouth ulcers, ask your doctor about other pain relief options.

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Canker Sore (Aphthous Ulcer)

Written by WebMD Editorial Contributors

Medically Reviewed by Sabrina Felson, MD on May 12, 2021

In this Article

  • What Is a Canker Sore?
  • Canker Sore Causes and Risk Factors
  • Canker Sore vs. Cold Sore
  • Canker Sore Symptoms
  • Canker Sore Diagnosis
  • Canker Sore Treatment
  • Canker Sore Home Remedies
  • Canker Sore Prevention

What Is a Canker Sore?

A canker sore is a small, shallow open wound (or ulcer) in your mouth that can make eating and talking uncomfortable. They’re also known as aphthous ulcers. There are a few types of canker sores:

  • Minor canker sores. These may show up three or four times a year. They typically happen in people ages 10 to 20. They’re less than 1 centimeter across and heal in about a week with no scarring.
  • Major canker sores. These are less common. The ulcers are bigger and can last more than 2 weeks. They often heal with scarring.
  • Herpetiform canker sores. These are rare and show up as clusters of tiny ulcers. They usually heal in about a week.

 

Canker Sore Causes and Risk Factors

Doctors don’t know what exactly causes most canker sores. 

Things that might cause minor sores include:

  • Stress 
  • Tissue injury, like from a sharp tooth or a dental appliance
  • Certain foods, including citrus or acidic fruits and vegetables (such as lemons, oranges, pineapples, apples, figs, tomatoes, and strawberries)
  • Nonsteroidal anti-inflammatory drugs like ibuprofen
  • An allergy to something in your food or in your toothpaste or mouthwash
  • Helicobacter pylori, the bacteria that can cause peptic ulcers

Things that might cause complex canker sores include:

  • An underlying health condition like a weakened immune system, HIV/AIDS, lupus, or Behcet’s disease
  • Nutritional problems like too little vitamin B12, zinc, folic acid, or iron
  • Gastrointestinal diseases like celiac or Crohn’s

About 1 in 5 people gets canker sores regularly. They’re more common in women, possibly because of hormonal differences. They may also run in families.

Canker Sore vs. Cold Sore

Canker and cold sores aren’t the same. 

Cold sores, also called fever blisters or herpes simplex type 1, are groups of painful, fluid-filled blisters. Unlike canker sores, a virus causes cold sores, and they’re highly contagious. Also, cold sores typically appear outside your mouth -- usually under your nose, around your lips, or under your chin -- but canker sores show up inside your mouth.

Canker Sore Symptoms

You may have a canker sore if you have:

  • A tingling or burning sensation, often 6 to 24 hours before a canker sore
  • Small sores in your mouth that are round or oval, white, gray, or pale yellow with a red edge or border
  • A painful sore or sores that appear alone or in clusters inside your mouth: on your tongue, at the base of the gums, on your soft palate (the back portion of the roof of your mouth), or inside your cheeks

Severe canker sore attacks may also cause:

  • Fever
  • Fatigue
  • Swollen lymph nodes

Canker Sore Diagnosis

 

Canker sores usually aren’t serious. Call your dentist if you have:

  • Unusually large sores
  • Sores that spread
  • Sores that last 3 weeks or longer
  • Extreme pain despite avoiding trigger foods and taking over-the-counter pain medication
  • Trouble drinking enough fluids
  • A high fever with canker sores
  • Frequent or lasting mouth sores, which may be a sign of an underlying problem, such as a serious skin disorder called pemphigus, celiac disease, inflammatory bowel disease, Behcet's disease, autoimmune disease, anemia, HIV, or, in rare cases, oral cancer or leukemia

They can usually make a diagnosis based on a physical exam and your medical history. They might want to test your blood to see whether a vitamin deficiency or another health condition is causing the sores.

Canker Sore Treatment

Pain from a canker sore tends to get better in a few days, and the sores usually heal without treatment in about a week or two. Treatment for large, long-lasting, or unusually painful sores might include:

  • Mouthwashes. Your doctor can prescribe a rinse that has a steroid or a painkiller.
  • Topical medications. Your doctor may prescribe a topical medication containing a steroid for the inflammation, and a topical analgesic like lidocaine to relieve pain. Aphthasol, a prescription ointment described as an "oral paste," may reduce pain and healing time.
  • Oral medications. The ulcer drug sucralfate (Carafate) and the gout drug colchicine (Mitigare) can also treat canker sores. Or your doctor might give you steroid pills.
  • Nutritional supplements. You might need these if a nutrient deficiency is causing your canker sores.   
  • Cautery. Dental lasers can help you feel better right away. Your doctor can also cauterize sores with chemicals like debacterol or silver nitrate.

Canker Sore Home Remedies

Home treatments to speed healing and help you feel better include:

  • Topical products. Medicated gels, creams, pastes, and liquids go on the sore.
  • Mouth rinses. Mix salt or baking soda in warm water, and swish it around your mouth.
  • Milk of magnesia. Put a bit on a cotton swab, and dab it on the sore.

Canker Sore Prevention

There’s no cure for canker sores, and they often come back. But you might get them less often if you:

What does sores in the mouth indicate?

Mouth sores, which include canker sores, are usually a minor irritation and last only 1 or 2 weeks. In some cases, they can indicate an infection from a virus, such as herpes simplex, or more severe causes, such as mouth cancer.

How do you get rid of inside mouth sores?

Rinse your mouth. Use salt water or baking soda rinse (dissolve 1 teaspoon of baking soda in 1/2 cup warm water). Dab a small amount of milk of magnesia on your canker sore a few times a day. Avoid abrasive, acidic or spicy foods that can cause further irritation and pain.

What virus causes sores inside mouth?

Some mouth sores are caused by the herpes virus. This is one of the germs that cause cold sores or fever blisters.