What Are Black Spots on the Lips?

Medically Reviewed by Dany Paul Baby, MD on February 17, 2023
4 min read

Your lips have thinner skin than most body parts. They're more likely to get lesions, sun damage, discoloration, and other conditions. Here are some causes of darker spots that can appear on your lips. If any of these are a concern for you, check with your doctor to learn more about what may be causing them.

This rare skin disorder causes flat brown spots on the lips and the mouth's mucous membranes. The reason for this condition is still unknown, but it doesn't appear to have any connection to systemic diseases. If you suspect you might have Laugier-Hunziker syndrome, you won't need medical intervention. If you're bothered by the appearance of these dark spots, you can treat them with laser therapy.

This rare, inherited disorder has a known connection to stomach cancer. The gene mutation caused by this condition is responsible for abnormal cell growth. That's why people with Peutz-Jeghers syndrome often have dark spots on the lips and inside the mouth. Other common areas are the eyes, nose, hands, feet, and anus.

People with Peutz-Jeghers syndrome also often have benign gastric tumors called hamartomas. These masses can become malignant (cancerous) over time if unattended. There are a number of treatments for this condition, including: 

  • Annual complete blood count tests and physical examination of cancer-prone areas
  • Regular removal of bleeding or large gastric polyps
  • Laparotomy or surgical intervention to find intestinal obstructions or bleeding. 

Dark marks on the lips can appear for many other reasons, often related to dryness or sun damage. In most cases, they don't mean there’s a dangerous skin condition and are likely to go away on their own. Keep your lips hydrated to avoid "farmer's lip," persistent dryness of the lips due to longtime sun exposure. Sometimes people with chapped lips tend to bite off the skin flakes. Doing this might cause bleeding and scabs, which could lead to stubborn pigmentation in some spots.

If the dark spots on your lips persist, a certified dermatologist can take a closer look to rule out any serious conditions. Some other causes of black spots on the lips include:

Skin discoloration. Melasma is a common skin condition that affects areas with regular sun exposure. It can cause gray and brown spots on your nose, forehead, and cheeks. Sun protection and lightening creams can help lessen the problem in most cases.

Hormonal changes during pregnancy. This is partly why women are more likely to have this problem. It can also be due to hormonal medications such as birth control pills or hormone replacement therapy. If untreated, melasma-related skin darkening can last for years.

Sun damage. Long-term exposure to ultraviolet rays without protection is to blame for many skin problems. Thickened, ulcerated spots called actinic keratoses are precancerous skin lesions that can become a more invasive form of skin cancer when untreated. If you think you have actinic keratoses on your lips, talk to your doctor. A dermatologist can detect and remove them using liquid nitrogen therapy (cryotherapy).

Standard at-home treatment for actinic keratosis includes topical medication. The FDA has  approved the use of 5-fluorouracil (5-FU), diclofenac sodium, and imiquimod creams for this purpose. To prevent actinic keratosis flares, use an SPF 50 sunscreen every day.

Iron overload. You might believe that there's no such thing as too much iron. But the excess of this mineral can cause hemochromatosis, a disorder where iron builds up in joints and organs. People with hemochromatosis can have skin darkening on the lips and other spots. Other common symptoms are:

  • Joint and belly pain
  • Weakness and fatigue
  • Loss of sex drive and impotence
  • Heart and liver failure
  • Memory fog
  • Diabetes

‌Doctors use regular blood drawing as a method to treat this condition.

If your black spots on the lips cause extreme discomfort or change in size, color, or texture, it's time to visit your doctor's office. They can look at the marks and refer you to a specialist when needed.