5 Warning Signs Your Moles Can Be Hiding a Skin Cancer

Skin cancer is one of the most common types of cancer, yet it often goes unnoticed in its early stages. It can be sneaky, disguising itself as a harmless mole or a subtle skin change that seems insignificant. While most moles are benign, some can develop into melanoma, the deadliest form of skin cancer. Recognizing the warning signs early can make a life-saving difference, as early detection significantly increases the chances of successful treatment.

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Asymmetry

Melanoma often presents as an asymmetrical mole, meaning one half looks different from the other. If you were to draw a line down the middle, the two halves wouldn’t match. In contrast, benign (non-cancerous) moles tend to have a balanced, uniform shape, where both sides mirror each other.

Asymmetry is something to keep an eye on. If you notice an irregular shape or a mole that appears lopsided, it’s important to have it evaluated by a dermatologist as soon as possible.

Color variations

Melanoma moles often exhibit uneven or multiple colors. While benign moles are usually a single, uniform shade of brown or tan, cancerous moles may display a mix of black, brown, tan, red, white, blue, or even gray within the same lesion. If you notice a mole that has developed multiple colors or has changed in pigmentation over time, it’s essential to get it checked by a dermatologist.

Growing in size

A mole that is growing in size—especially one that gets larger over time—can be a red flag for melanoma. While benign moles typically remain the same size throughout adulthood, a cancerous mole may expand in diameter, becoming wider or more raised. A general guideline is the "6mm rule"—if a mole is larger than a pencil eraser (about 6 millimeters) or continues to grow, it should be examined by a dermatologist.

However, melanoma can also develop in smaller moles, so any noticeable increase in size, thickness, or elevation should not be ignored.

Irregular borders

A mole with irregular, uneven, or blurred borders can be a warning sign of melanoma. Benign moles typically have smooth, well-defined edges, while cancerous ones often appear jagged, notched, or poorly defined, blending into the surrounding skin. These irregular borders occur because melanoma cells grow in an uncontrolled and disorganized manner, spreading into nearby tissue. Any mole with changing or unclear borders should be evaluated by a dermatologist as soon as possible.

Bleeding or crusting

A mole that bleeds, crusts, or doesn’t heal can be a serious warning sign of melanoma or another type of skin cancer. Benign moles typically remain smooth and intact, while cancerous ones may develop scabs or cracks. Persistent bleeding or an inability to heal properly is a red flag, as healthy skin usually repairs itself quickly. Any mole showing these signs should be checked by a dermatologist without delay.

Moles are a natural occurrence on the skin, often forming due to clusters of pigment-producing cells. Recognizing changes in their shape, size, or color is crucial for early detection and timely medical intervention.