People's lips can vary in color and appearance depending on several factors, such as their natural skin tone, sun exposure levels, and overall health.

A person can experience lip discoloration after consuming things that contain pigments, such as berries, beets, and wine. Lip discoloration can also be the result of sun damage, nutritional deficiencies, or an underlying medical condition.

This article looks at the different causes of lip discoloration, the treatments available, and how to prevent it.

a woman with lip discoloration due to Cyanosis. Image credit: Ciernik M, 2016 Share on Pinterest
Cyanosis is a possible cause of lip discoloration.
Image credit: Ciernik M, 2016

Blood changes color depending on its oxygen content. For example, oxygenated blood appears bright red, while deoxygenated blood can appear either dark red or purple.

Low oxygen content in the blood or poor circulation can cause blueish discoloration in the skin and lips. This is known as cyanosis. Cyanosis occurs when the oxygen saturation levels in a person's blood fall below 85%.

A person may also develop cyanosis if they have abnormal hemoglobin.

Hemoglobin is a protein present in the blood. Normal hemoglobin adheres to oxygen molecules and transports them throughout the blood.

However, the presence of abnormal hemoglobin can significantly reduce the oxygen content of the blood.

Other possible causes of cyanosis include:

  • pneumonia
  • fluid buildup in the lung cavity
  • blood clots
  • heart attack
  • exposure to toxins
  • exposure to freezing temperatures
  • spending time at high altitudes

Cyanosis usually indicates an underlying medical condition that requires treatment. A person should seek medical care if they experience any of the following symptoms of cyanosis:

  • shallow breathing or difficulty breathing
  • headaches that occur more often than usual
  • fatigue or muscle weakness
  • chest pain
  • confusion
  • dizziness or loss of coordination

Iron deficiency anemia occurs when a person does not have enough iron in their body.

The symptoms of anemia vary depending on the severity. People who have mild iron deficiency anemia may not experience any symptoms at all.

However, in other cases, the following can occur:

  • chest pain
  • fatigue
  • dizziness
  • headache
  • shortness of breath
  • irregular heartbeat
  • brittle nails
  • pale or white lips
  • cracked skin at the sides of the mouth

When a person has an excess of iron in the body, it can cause hemochromatosis. One symptom of hemochromatosis is skin hyperpigmentation. This may result in discoloration of the lips.

Some other symptoms of hemochromatosis include:

  • joint inflammation
  • fatigue
  • abdominal pain
  • unintentional weight loss
  • liver disease
  • low libido
  • erectile dysfunction

Oral candidiasis, or oral thrush, occurs when an overgrowth of the Candida fungus develops in the mouth.

Oral thrush can cause white or yellow patches on the inner cheeks, tongue, gums, or lips, as well as:

  • redness or soreness in the mouth
  • pain when eating or swallowing
  • dry, cracked skin at the corners of the mouth and lips
  • a bad taste in the mouth
  • loss of taste

Dark, crusty bumps called actinic keratosis, or sunspots, may develop due to sun exposure. They can appear on areas of skin including the lips, face, back, chest, and arms.

Sunspots vary in size and color, ranging from light tan to dark red.

Not all actinic keratosis lesions are cancerous. However, an estimated 10–15% of lesions will develop into squamous cell carcinomas, according to the American Osteopathic College of Dermatology.

Precancerous actinic keratosis legions usually feel tender or painful to the touch, and they may appear red or inflamed.

Laugier-Hunziker syndrome is a benign skin condition that causes dark brown spots, called macules, on the lips and the lining of the mouth.

Macules can be 2–5 millimeters in diameter and also occur on the tips of the fingers and toes.

Laugier-Hunziker syndrome does not require medical treatment. However, some people choose to have macules removed for aesthetic reasons.

Some people may experience hyperpigmentation and other skin changes as a side effect of certain medications.

These may include:

  • cytotoxic drugs, which doctors use to treat cancer
  • antipsychotics
  • anticonvulsants
  • antimalarials
  • tetracyclines, which doctors use to treat bacterial infections
  • medicines that contain heavy metals

Red, inflamed, or dry lips may occur as a result of an allergic reaction to ingredients present in cosmetics and oral hygiene products.

Some possible irritants include:

  • lipsticks
  • leather
  • rubber
  • latex
  • topical antibiotics
  • products containing fragrances, preservatives, or metals

An allergic reaction involving the lips can cause:

  • redness and swelling
  • dry, flaky skin
  • hypersensitive skin
  • bleeding
  • pain

These symptoms will usually improve once a person stops using the product that caused the allergic reaction.

However, people who experience persistent or worsening symptoms should contact a doctor.

Treatment options for lip discoloration vary depending on the underlying cause.

For example, people who develop lip discoloration as a result of taking a certain medication can speak with their doctor about alternative treatment options.

Doctors can treat oral thrush with antifungal medications in the form of tablets, lozenges, or mouthwash.

Other medical treatments for lip discoloration include:

  • laser therapy
  • light therapy
  • chemical peels
  • liquid nitrogen spray
  • medicated ointments, such as 5-fluorouracil and Solaraze

The following natural compounds may help reduce hyperpigmentation, according to a 2018 systematic review in the Journal of Clinical and Aesthetic Dermatology:

  • aloe vera gel
  • mulberry extract
  • liquiritin, which is a compound derived from licorice
  • fungal extracts, such as kojic acid and lignin peroxidase
  • niacinamide, which occurs in root vegetables
  • green tea extract
  • turmeric
  • vitamin C

People can prevent various causes of lip discoloration by:

  • practicing proper oral hygiene
  • avoiding or quitting smoking
  • limiting sun exposure and wearing a lip balm with sunscreen
  • eating a balanced diet that contains a range of nutritional foods

A person should contact their doctor if they are concerned about the appearance of their lips. A doctor can diagnose different types of discoloration affecting the lips.

People should also seek medical attention if they experience any of the following symptoms:

  • irregularly shaped skin lesions
  • a skin lesion that bleeds, grows quickly, does not heal, or is tender to the touch
  • blue skin or lips
  • difficulty breathing
  • chest pain

Lip discoloration can occur as a result of a fungal infection, iron deficiency anemia, sun exposure, or an allergic reaction. Treatments for lip discoloration vary depending on the cause.

People who notice new or unusual spots on their lips may want to contact their doctor. Some types of sunspots on the lips can develop into skin cancer if a person does not receive treatment for them.

Blue lips may indicate poor circulation or a lack of oxygen in the blood. People should seek immediate medical attention if they have blue lips accompanied by any of the following symptoms:

  • difficulty breathing
  • irregular heartbeat
  • persistent or severe headache
  • numbness in the limbs
  • dizziness