Mole monitoring is really important as part of your preventative health screening. Patients often ask about what the best way to monitor their moles is, and the ABCDE rule can be quite useful. So, A is the Asymmetry. So, does a mole look the same on both sides? Can you draw a line through it horizontally and vertically, and does it look the same? If it's asymmetrical, that is a bit of a warning sign. B is the Border of the mole. And the way that I think about that is, "Can I get a pen and can I evenly trace around the edge of the mole? Or are the edges quite jagged and you can't quite make out what's going on?" If a mole is quite irregular in its edges and you can't get that nice even border around it, that's a worrying sign. C is the Colour. And the colour of the mole, if there are more than two or three colours within a mole, that's an alarm sign. That's a sign you should go and see a dermatologist. D is the Diameter. And a mole, really, that's bigger than about half a centimetre, six millimetres, should be reviewed. And then E is Evolving Change. So, anything that changes in its size, its shape, or its colour, should be looked at.