Most people experience red bumps or spots on the roof of their mouth at some point. Common causes include irritation from foods, dentures, or a mouth or throat infection.

Red spots on the roof of the mouth can be irritating, but they are usually harmless and should go away on their own. People can see a doctor if they are concerned or do not know what is causing the spots, as it can also be a sign of something more serious.

In this article, we look at factors that can cause red spots on the roof of the mouth, pictures to help identify the cause, and prevention.

Strep throat infection

Strep throat is an infection that affects the throat and tonsils. A group of bacteria called Streptococcus are responsible for this infection.

Tiny, red spots called petechiae on the roof of the mouth are a common symptom of strep throat infection.

Other symptoms of strep throat include:

  • fever
  • pain while swallowing
  • red and swollen tonsils
  • swollen lymph nodes in the neck

If a person suspects they have strep throat, they should see a doctor or an ear, nose, and throat specialist. Treatment usually includes a course of antibiotics, drinking plenty of fluids, and rest.

Physical injury

One of the most common reasons for a red spot or sore on the roof of the mouth is a sudden injury such as a cut or burn. This may happen because of drinking something too hot or from eating food that causes bruising from biting or chewing.

Other conditions that could lead to physical injury or bruising of the mouth are:

  • dentures that no longer fit properly
  • the edge of a broken tooth
  • uneven dental fillings or broken crowns or bridges
  • sensitivity or allergic reaction to certain ingredients in some toothpaste or mouthwash

The American Dental Association advise waiting 2 weeks to allow the damaged tissue to heal. If red spots persist, they recommend checking with a dentist to diagnose the condition.

Oral thrush

Also known as candidiasis, oral thrush is a yeast infection that the fungus Candida causes.

Nearly everyone has Candida present in their digestive tract or on the skin, but under certain conditions, the fungi multiply to cause an infection.

Some specific factors put people at a higher risk of oral thrush, such as:

Common symptoms of oral thrush include:

  • white or red patches on the inner cheeks, tongue, roof of mouth, and throat
  • red spots that feel sore
  • a loss of taste
  • a cottony feeling in the mouth
  • pain while eating and swallowing

If a person suspects that they have oral thrush, they can consult their doctor or dentist about their symptoms. A healthcare professional can usually diagnose oral thrush by examining the mouth. In some cases, they may ask for an oral swab of the mouth or throat to look at under a microscope.

Mouth ulcers

Mouth ulcers are sores that occur in the mouth. They cause discomfort and can make it difficult to eat and drink.

Mouth sores tend to clear in 2–4 weeks, but they can persist, bleed, or become infected in some cases.

Some common factors that contribute to mouth ulcers are:

  • dehydration
  • poor mouth care or oral hygiene
  • heavy alcohol use
  • using tobacco
  • a lack of dietary protein
  • vitamin deficiencies
  • certain medications or treatments, such as radiation therapy

By eating soft, bland foods and drinking lukewarm water, people can get some relief from mouth sores. An individual may also want to avoid foods that are coarse, salty, or acidic until the sores go away, as they can irritate the affected area and increase discomfort.

Hand, foot, and mouth disease

Hand, foot, and mouth disease (HFMD) is a common viral infection. It typically affects children who are less than 5 years old, though older children and adults can also get the virus.

The first sign of HFMD is often a fever. After 1–2 days, painful sores may develop in the mouth. Doctors call these herpangina. The sores usually begin as small, red spots, and they commonly appear at the back of the mouth. These spots can blister and may be painful.

HFMD often also causes a rash on the palms of the hands and soles of the feet, and sometimes on the knees, elbows, and genitals. Most cases are mild, and some people can have HMFD with no symptoms at all.

There is no treatment for HFMD, though people can use over-the-counter (OTC) medications to reduce pain and fever. Mouthwashes and oral sprays can help relieve mouth pain.

Oral herpes

The herpes simplex virus (HSV) causes herpes, which is a viral infection. This virus causes open sores, also called cold sores or fever blisters, in or around the mouth.

Cold sores are most common on the edges of the lips, but they can also appear inside the mouth, including the roof of the mouth. They often appear as white, open sores, though they can also look like red spots, especially when just beginning to form and when healing.

More than half of Americans who are 14 to 49 years of age carry HSV. People may notice that cold sores appear when their immune system is weakened, such as in cold weather or after another infection or illness.

Cold sores usually clear on their own within 2 weeks. During this period, people should avoid close physical contact with others and avoid sharing personal items such as razors, toothbrushes, lip balms, and towels to prevent transmission of the virus.

Canker sores

Canker sores are small ulcers that develop on the roof or the inside of the mouth. Canker sores look like ulcers with a grey, yellow, or white center and a flat, red border. They begin with a red spot or bump and tend to grow in size in a few days.

The exact cause of canker sores remains unknown, but some risk factors include:

  • genetics
  • fatigue
  • emotional stress
  • certain foods that cause irritation

Unlike cold sores, which oral herpes causes, canker sores are not contagious and heal in 7–10 days. In this time, people can relieve discomfort by using OTC topical creams, gels, and antimicrobial mouth rinses.


Erythroplakia is a red patch or spot commonly seen on the floor or side of the mouth. Doctors do not fully understand the causes of erythroplakia, but it is more common in people who use tobacco or alcohol to excess.

The characteristics of erythroplakia include the following:

  • smooth, velvety lesions that feel soft to touch
  • lesions surrounded by a well-defined margin
  • a painful, burning sensation
  • a metallic taste in the mouth

According to the International Agency for Research on Cancer, erythroplakia is often an early sign of oral cancer.

People who suspect erythroplakia should see their doctor. In some cases, a doctor may recommend removing the tissue with surgery or laser treatment to prevent cancerous tissue from developing.


Here are some easy tips to improve overall oral hygiene and reduce the risk of oral health conditions:

  • maintain oral health by brushing teeth twice daily
  • use a mouthwash or rinse at least once a week
  • do not use tobacco products
  • if any medication causes dry mouth, drink plenty of water, chew sugarless gum, and limit alcohol
  • visit the dentist regularly


Many conditions can cause red spots in the mouth, some of which are harmless and resolve on their own.

Some red spots may indicate an oral infection. If symptoms last longer than a week or are very painful, it is best for people to consult a doctor.

Treatment depends on the underlying cause of the condition and can include oral gels and balms, mouth rinses, and antibiotics.