Melanoma: Symptoms and Signs

Approved by the Cancer.Net Editorial Board, 02/2023

ON THIS PAGE: You will find out more about the changes and medical problems that can be a sign of melanoma. Use the menu to see other pages.

What are the symptoms and signs of melanoma?

People with melanoma may experience one or more of the symptoms or signs described below. Symptoms are changes that you can feel in your body. Signs are changes in something measured, like taking your blood pressure or doing a lab test. Together, symptoms and signs can help describe a medical problem.

"ABCDE" rule

Changes in the size, shape, color, or feel of a mole or skin lesion are often the first warning signs of melanoma. A skin lesion is an area of skin that is different from the surrounding skin. These changes can occur in an existing mole or lesion, or melanoma may appear as a new or unusual-looking mole or lesion. The "ABCDE" rule is helpful in remembering the warning signs of melanoma:

  • Asymmetry. The shape of one-half of the skin lesion does not match the other.

  • Border. The edges are ragged, notched, uneven, or blurred.

  • Color. Shades of black, brown, and tan may be present. Areas of white, gray, pink, red, or blue may also be seen.

  • Diameter. The diameter is usually larger than 6 millimeters (mm) or has grown in size. This is about 1/4 inch in diameter, about the size of a pencil eraser. Melanoma may be smaller when it is first detected.

  • Evolving. The mole or lesion has been changing in size, shape, color, or appearance, or it is growing in an area of previously normal skin. Also, when melanoma develops in an existing mole or lesion, its texture may change and become hard or lumpy. The mole or lesion may feel different and may itch, ooze, or bleed, but a melanoma skin lesion usually does not cause pain.

When to see a doctor

Many melanomas are dark brown or black and are often described as changing, different, unusual, or “ugly looking,” meaning that it looks different from the typical moles a person has. However, any skin abnormality that is growing or changing quickly and does not go away, whether colored or not, should be examined by a doctor. Bleeding may be a sign of more advanced melanoma. In addition, the appearance of a new and unusual mole is more likely to be melanoma.

If you are concerned about a new or existing mole, please talk with your family doctor or a dermatologist. Your doctor will try to understand what is causing your symptom(s). They may do an exam and order tests to understand the cause of the problem, which is called a diagnosis, and to figure out if a biopsy is recommended.

The next section in this guide is Diagnosis. It explains what tests may be needed to learn more about the cause of the symptoms. Use the menu to choose a different section to read in this guide.