How to Get Rid of Canker Sores? A Doctor-Reviewed Answer

Most canker sores are harmless, painful mouth ulcers that improve on their own within 1 to 2 weeks. The best way to get rid of canker sores is usually a combination of gentle mouth care, avoiding irritation, and using doctor- or pharmacist-recommended pain-relief treatments when needed.

Overview: how to get rid of canker sores

For most people, the answer to how to get rid of canker sores is reassuring: these small, shallow mouth ulcers usually heal on their own within 1 to 2 weeks. In the meantime, the most helpful steps are to reduce irritation, keep the mouth clean, and use simple treatments that ease pain and protect the sore while it heals.

Canker sores, also called aphthous ulcers, are not the same as cold sores. They are not caused by herpes virus and are not contagious. They typically appear inside the mouth, such as on the inner lips, cheeks, tongue, soft palate, or gums, and they can make eating, drinking, and brushing uncomfortable.

Because canker sores are common and often harmless, many people can manage them at home. Still, persistent, unusually large, or frequently recurring mouth ulcers deserve medical attention, because a doctor may need to rule out irritation from dental issues, nutritional deficiencies, infections, inflammatory disorders, or other oral conditions.

What canker sores feel and look like

Canker sores are usually round or oval ulcers with a white, yellow, or gray center and a red border. Before the ulcer becomes visible, there may be a tingling, burning, or sore feeling in one area of the mouth. The pain is often stronger than the size of the sore would suggest.

They may be single or appear in small clusters. Minor canker sores are the most common type and are usually less than 1 centimeter across. Larger ulcers can be deeper, more painful, and slower to heal, while herpetiform ulcers are tiny but can occur in groups and merge into larger painful areas.

Symptoms can become more noticeable with acidic foods, spicy meals, salty snacks, alcohol-based mouthwashes, or friction from braces, dentures, or a sharp tooth edge. If a mouth sore is on the lips’ outer border or forms blisters before crusting, that pattern is more typical of a cold sore than a canker sore.

Why canker sores happen

Doctors do not always find one single cause. In many people, canker sores develop when the mouth lining becomes irritated or the immune system reacts to a trigger. A small injury from biting the cheek, brushing too hard, dental work, or poorly fitting oral appliances can start the process.

Other common triggers include emotional stress, lack of sleep, and certain foods. Citrus fruits, tomatoes, pineapple, spicy dishes, chocolate, coffee, and rough or salty snacks may aggravate the mouth in some people. Toothpastes or mouth rinses containing sodium lauryl sulfate can also be irritating for sensitive individuals.

Recurring or severe sores sometimes relate to underlying issues such as iron, folate, vitamin B12, or zinc deficiency; inflammatory bowel disease; celiac disease; hormonal changes; or immune-related conditions. A clinician may also consider whether a sore could be related to another mouth problem that needs different care, including oral cancer or significant gum and soft tissue disease.

• Minor mouth injury or friction
• Stress and fatigue
• Acidic, spicy, or abrasive foods
• Nutritional deficiencies
• Hormonal changes
• Inflammatory or immune-related conditions
• Dental irritation from braces, dentures, or a sharp tooth

What helps canker sores heal faster

There is no instant cure, but several steps can help canker sores feel better and heal with less irritation. The first goal is to protect the sore. Soft foods, lukewarm drinks, and careful brushing with a soft toothbrush can reduce friction. Many people also benefit from avoiding spicy, acidic, salty, or crunchy foods until the ulcer settles.

Over-the-counter or prescription products may also help. These can include protective pastes or gels that coat the sore, antiseptic or anti-inflammatory mouth rinses, and topical medicines that reduce pain and inflammation. A doctor or dentist may recommend a steroid-based treatment for more painful or recurrent ulcers. If a dental source of trauma is contributing, treatment by a specialist may be needed, sometimes involving dentistry or evaluation by oral and dental health teams.

Simple self-care measures can also make a difference. Sipping water often, avoiding smoking, and not picking at the ulcer can support healing. If a person repeatedly develops sores after specific foods or products, keeping a symptom diary can help identify triggers. When ulcers are linked to a vitamin or iron deficiency, correcting that deficiency is often an important part of treatment.

• Use a soft toothbrush and brush gently
• Choose bland, soft foods while the sore is active
• Avoid acidic, spicy, salty, and sharp-textured foods
• Consider protective gels, medicated rinses, or doctor-advised topical treatments
• Stay well hydrated
• Address dental irritation if present

How a doctor diagnoses recurring or severe mouth ulcers

If a canker sore is unusual, severe, or keeps coming back, a doctor will usually begin with a careful history and mouth examination. They may ask when the sores started, how often they appear, what they look like, whether there is fever or digestive trouble, and whether certain foods, stress, or trauma seem to trigger them.

The examination often includes looking at the ulcer’s size, shape, number, location, and the surrounding tissues. The doctor may also check the teeth, gums, tongue, and throat for signs of friction, infection, inflammation, or another condition that can mimic a canker sore. In selected cases, they may coordinate care with ear, nose and throat or dental specialists.

Additional tests are not needed for most simple canker sores. However, blood tests may be ordered if ulcers are frequent, severe, or associated with fatigue, weight loss, diarrhea, or other ongoing symptoms. These tests may look for anemia, vitamin deficiencies, celiac disease, or inflammatory conditions. If a sore looks atypical or does not heal, a biopsy may be recommended to rule out other causes.

When to seek medical care

Most canker sores do not require urgent medical treatment, but some situations should not be ignored. A person should arrange medical or dental review if a sore lasts longer than 2 weeks, becomes unusually large, spreads widely, or keeps returning. Medical advice is also important if mouth pain is so severe that eating, drinking, or oral hygiene becomes difficult.

Other red flags include fever, swollen lymph nodes, unexpected weight loss, blood in the stool, ongoing abdominal symptoms, or sores appearing elsewhere on the body. These features may point to a broader health issue rather than a simple isolated mouth ulcer. A new persistent ulcer in an adult, especially with tobacco or alcohol exposure, needs timely assessment to exclude more serious causes.

International patients who need multidisciplinary evaluation can be assessed at Acibadem International, where JCI-accredited hospitals bring together dental, ENT, gastroenterology, and internal medicine specialists for diagnosis and treatment.

Prevention and long-term self-care

People who get canker sores repeatedly often benefit from prevention rather than treating each episode only after it starts. The most practical approach is to identify personal triggers and reduce irritation in the mouth. This may include switching to a softer toothbrush, being careful with hard or sharp foods, and asking a dentist to smooth a rough tooth edge or adjust oral appliances.

Balanced nutrition matters, especially if ulcers are frequent. A clinician may check for low iron, folate, vitamin B12, or zinc when there is a pattern of recurrence. Good sleep, stress management, and regular meals may also help some people reduce flare-ups. These habits do not guarantee prevention, but they can make episodes less common for some individuals.

It is also wise not to assume every recurring mouth ulcer is simply a canker sore. If symptoms are frequent or changing, professional review helps confirm the diagnosis and guide treatment. This is particularly important when ulcers occur along with digestive symptoms, rashes, joint pain, or persistent gum inflammation, which may overlap with other conditions such as Crohn's disease.

Frequently asked questions

How long do canker sores usually last?

Most minor canker sores improve within 7 to 14 days and do not leave a scar. Larger or deeper ulcers may take longer. If a sore lasts more than 2 weeks, it should be checked by a doctor or dentist.

What is the fastest way to get rid of canker sores?

There is no true instant cure, but healing is usually more comfortable when the sore is protected from irritation. Gentle oral care, avoiding trigger foods, and using pharmacist- or doctor-recommended topical treatments can reduce pain and support recovery.

Are canker sores contagious?

No. Canker sores are not contagious and cannot be passed from person to person by kissing, sharing utensils, or close contact. They are different from cold sores, which are caused by a contagious virus.

Why do I keep getting canker sores?

Repeated canker sores may be triggered by stress, mouth injury, certain foods, dental irritation, or sensitivity to some oral care products. In some cases, they are linked to vitamin or mineral deficiencies, digestive disorders, or immune-related conditions, so recurrent ulcers may need medical review.

Should a canker sore be biopsied?

Most typical canker sores do not need a biopsy. A doctor may recommend one if the ulcer looks unusual, is very large, does not heal as expected, or raises concern for another diagnosis.

Can children get canker sores?

Yes, children and teenagers can develop canker sores, and they are often harmless. However, children should be assessed if sores are frequent, severe, accompanied by fever, or make drinking difficult.

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.