A black spot inside your cheek is most likely a harmless condition such as a mole or hyperpigmentation. In very rare cases, it could be a type of cancer called oral melanoma.

Finding a black spot or dot on the inside of your cheek can be alarming, but it’s not necessarily a sign of something serious.

A variety of harmless conditions can cause discoloration in your mouth, such as moles, hyperpigmentation, and leakage from your dental fillings.

In extremely rare cases, a black spot may be a sign of a type of cancer called oral melanoma. Oral melanoma accounts for about 1.6 percent of cancers of the head or neck, and less than 1 percent of all melanomas, according to The Oral Cancer Foundation.

Keep reading to find out what may be causing a black spot on the inside your cheek and when you should see your doctor.

The following conditions may cause a black dot, a small, circular mark, to form on the inside of your cheek.

Oral nevi

Oral nevi are small brown, bluish gray, or almost black dots that can appear inside your mouth. Nevi is a medical term for moles (nevus is singular).

Oral nevi are usually slightly raised. They’re more common on the roof of the mouth or inner lip, but they can also form on the cheeks. They usually don’t cause any symptoms.

No treatment is usually necessary for an oral nevus, and there are no reports of an oral nevus becoming cancerous. However, your doctor or dentist may still recommend getting a biopsy to make sure it’s indeed a nevus and not melanoma.

Blood blister

Blood blisters are sacs of fluid that fill with blood. They can range in color from purple to dark red. They commonly form when the skin in your mouth gets pinched.

Blood blisters are often big enough that you can feel them with your tongue. They most often form on the soft parts of your mouth, like your cheek or inner lips. They’re typically painful when touched, or if you eat spicy food.

The majority of blood blisters don’t last long and don’t need treatment if you leave them alone. But if the blood blister lasts for more than 2 weeks or becomes a reoccurring problem, it’s a good idea to visit your doctor.

Melanotic macules

Oral melanotic macules are areas of hyperpigmentation that average about a quarter of an inch in diameter. They can be as small as 0.04 of an inch. These spots are typically flat and have a well-defined border.

Oral melanotic macules are noncancerous, but your doctor may recommend a biopsy to rule out melanoma.

The following are potential causes of dark spots on the inside of your cheek. Spots can vary in size but they are larger than a dot.

Leakage from a dental filling

Amalgam is a material made of mercury, tin, zinc, silver, and copper. It’s been used for more than 150 years for dental fillings.

Amalgam tattoos are leakages from these dental fillings. They’re relatively common and usually appear dark blue, gray, or black. They’re most often located next to a filling.

Amalgam tattoos don’t cause any symptoms and don’t need treatment. They’re permanent unless removed with laser surgery.

Smoker’s melanosis

Smoking can leave blotchy stains called smoker’s melanosis inside your cheeks and gums. About 22 percent of people who smoke have this staining.

These stains don’t cause symptoms and don’t need treatment. However, your doctor will likely recommend a biopsy to rule out other conditions. The stains can be removed with laser treatment or electrosurgery.

Oral cancer

Melanoma is a type of skin cancer that affects pigmented cells called melanocytes.

Melanoma is most common on parts of your skin frequently exposed to sunlight, but it can also form in your mouth and nose. In extremely rare cases, a dark spot inside your cheek may be a sign of oral melanoma.

In its early stages, oral melanoma often has minimal symptoms. It usually manifests as a dark brown to blue-black spot. It can also be unpigmented or white. In its late stages, the spot may be accompanied by pain, ulcers, and bleeding.

The average age of diagnosis of oral melanoma is 56. Oral cancer is twice as common in men as women.

Treatment for oral melanoma may include:

Peutz-Jeghers syndrome

Peutz-Jeghers syndrome is a condition that causes noncancerous growths called polyps in the intestines and stomach.

Children who develop this condition also commonly develop dark spots on their lips, inside their mouth, near their eyes and nose, and around their anus. The spots usually fade with age.

People with Peutz-Jeghers syndrome also often develop complications such as pain, bleeding, or bowel obstruction.

There’s no current cure for Peutz-Jeghers syndrome, but surgery can remove the polyps in the digestive tract.

Addison’s disease

Addison’s disease, or adrenal insufficiency, is a deficiency of the hormones produced by your adrenal glands. One of the symptoms of Addison’s disease is hyperpigmented blotches of skin inside your mouth.

Other symptoms include:

You can take medication to replace the hormones your adrenal glands can’t produce by themselves.

Even though the chances of developing oral melanoma is very low, it’s good practice to see your doctor whenever you notice an abnormally colored spot or dot in your mouth.

It’s especially important to get the spot checked if you’re older than 55 years. Older adults have a higher risk for developing oral cancer.

Your doctor may use the following tests to help confirm a diagnosis of the dark spot inside your cheek:

  • Physical inspection. Your doctor may be able to identify the spot during a physical examination simply based on its appearance.
  • Biopsy. During a biopsy, your doctor will cut away a small piece of the spot and send it to a lab for analysis.
  • Blood test. Your doctor may administer a blood test measuring your potassium, cortisol, and ACTH hormone levels if they suspect Addison’s disease.

What are the first signs of tonsil cancer?

The first symptoms of tonsil cancer include:

  • a painless lump in your neck
  • sore throat
  • persistent hoarseness
  • difficulty or painful swallowing
  • unexplained weight loss

Make an appointment with a doctor or dentist if you’re experiencing any of these symptoms.

What causes black tonsil stones?

Tonsil stones, also called tonsilloliths, are hard formations that can build up on your tonsils. They’re caused by calcium that builds up around food, dead cells, or other debris that gets trapped in the crevices of your tonsils.

Tonsil stones are typically white or yellow in color. However, they may also be black depending on the debris or bacteria that has accumulated.

What does tonsil cancer look like?

The number one symptom or identifier of tonsil cancer is having one tonsil larger than the other. Other common symptoms includes a persistent sore throat or ear pain.

See a doctor if you notice or experience one of these symptoms.

What is the black spot on my tonsil?

A black spot on your tonsil might be what is called a “tonsillar crypt.” This is a normal part of your tonsil’s anatomy.

A black spot might also be a tonsil stone, which develop when debris becomes trapped in the pits of the tonsils. Tonsil stones are typically white or yellow in color, but they may also be black.

Finding a dark spot or dot in your mouth is unlikely to be a sign of cancer. However, it’s still a good idea to show it to your doctor or dentist. If it does turn out to be cancerous, getting an early diagnosis and treatment can improve your outlook.