May is skin cancer awareness month — a meaningful reminder to pause, check in with your body and take a proactive approach to your skin health.

Melanoma is one of the most serious forms of skin cancer — but here's the encouraging news: early detection generally improves treatment outcomes. One of the most powerful tools you have is also one of the simplest: knowing what to look for.

The ABCDE rule is a practical, easy-to-remember guide that can help you recognize changes in your skin that may warrant medical attention. Think of it as your personal skin health checklist.

The ABCDEs of melanoma

How to tell a normal mole from a potential concern.

	A — Asymmetry Healthy moles are typically symmetrical — meaning if you drew a line through the middle, both halves would look the same. Melanomas often are not. What to look for: One half that doesn’t match the other An uneven or irregular shape
	B — Border Healthy moles usually have smooth, well-defined edges. Melanomas may present with irregular borders. What to look for: What to look for: Jagged, scalloped, or blurred edges Borders that are not clearly defined
	C — Colour Most benign moles are a single, consistent shade. Melanomas may include multiple colours. What to look for: Variations in brown, black or tan Areas of red, white, blue or grey
	D — Diameter Size matters. Melanomas are often larger than 6 mm (about the size of a pencil eraser), though they can be smaller. What to look for: A mole that appears to be growing A spot that looks larger than others
	E — Evolving Change over time is one of the most important indicators. What to look for: Changes in size, shape or colour New symptoms such as itching, bleeding or crusting A mole that stands out from others

When to seek care*

If you notice any of the ABCDE signs—or any change that feels concerning—we encourage you to connect with a healthcare practitioner. Early assessment is key to achieving the best possible outcomes.

Why ongoing monitoring matters

While the ABCDE rule is an important starting point, many skin changes are subtle and occur gradually. Without a clear point of reference, these changes can be difficult to detect.

That’s why incorporating tools that support monitoring and tracking over time can make a meaningful difference in early detection.

Staying one step ahead

While the ABCDE rule is a powerful starting point, many skin changes are subtle and happen gradually. Without a clear point of reference, these changes can be easy to miss — even when you're paying close attention.

Regular visits with your primary care practitioner or dermatologist are an important part of staying ahead of your skin health. For those who want to take a more proactive approach, 3D Mole Mapping — can help establish a baseline and track changes over time.

Our 3D Mole Mapping service is available at our Vancouver, Calgary and Toronto Bay locations.

* This information is for educational purposes and should not replace professional medical evaluation.