There are numerous possible causes of red bumps or red spots on the roof of the mouth. 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 independently. If people are concerned or do not know what is causing the spots, they can see a doctor, as they 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 is an infection of the throat and tonsils. It is the result of an infection by Streptococcus bacteria.

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:

If a person suspects they have strep throat, they should contact their doctor. Treatment usually includes a course of antibiotics, drinking plenty of fluids, and rest.

One of the most common causes of 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 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

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

Nearly everyone has Candida in their digestive tract and skin, but the fungi multiply to cause an infection under certain conditions. 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 oral thrush, they can consult their doctor or dentist about their symptoms. A healthcare professional can usually diagnose oral thrush by examining the mouth. Sometimes, they may ask for an oral swab of the mouth or throat to look at under a microscope.

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 to 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 (HFMD) is a viral infection that typically affects children under 5 years old.

The first sign of HFMD is often a fever. After 1 to 2 days, sores known as herpangina may develop in 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.

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.

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.

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. Erythroplakia is often an early sign of oral cancer.

The characteristics of erythroplakia include the following:

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

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.