As a child of the 80s, I laid out in the sun. A lot. If you know me today, and observe the evidence of my Irish heritage (read that as “pasty white skin”), you might be surprised that I was able to acquire a suntan. Well I was with the help of baby oil and a reflective blanket. Yes, that was me ignoring all the warnings from the people who knew better. It seemed like a good idea at the time.

So now my skin shows signs of too much sun exposure from 30 years ago. I have dark spots, moles and wrinkled skin, but how do I know if these issues are more than cosmetic? It’s time to learn my ABCs.

A – Asymmetry – If you draw a line down the middle of the mole or dark spot, each half should be nearly identical. If they do not match, that is a red flag.

B – Border – The edges of the lesion should be smooth and even. If it looks like the edge is leaking color in some spots or has a wavy edge, this is considered an irregular border and is an indicator of possible malignancy.

C – Color – The lesion should be one uniform color. If the lesion is brown but contains some black spots, please have this checked by a dermatologist.

D – Diameter – Larger moles are more likely to be cancerous. Anything larger than the tip of a pencil eraser should be evaluated for possible malignancy. However don’t sleep on smaller moles. Keep an eye on them because the earlier cancer is caught, the easier it is to treat.

E – Evolving – If the lesion has changed, or is changing, this is a red flag. If it changes color, changes size, starts to bleed or suddenly becomes raised when it was flat before, these are all red flags. Make sure your doctor is aware of these changes.

Lesions that do not heal quickly should also be brought to your doctor’s attention. The sun is not the only culprit here. Anything that injures the skin can trigger cancer cells to grow. One of my patients burned her upper lip on a piece of piping hot pizza (haven’t we all been there?) The lesion was slow to heal and a dermatologist diagnosed and treated her for cancer.

Blue light emitted from your smartphone and computer screen can also cause photo damage to your skin. It is not always a single incident of skin damage that creates our problems, but the accumulation of damage. Be sure to protect your skin from all sources of damage.