Generally, moles are harmless growths that occur when skin cells containing melanin, the pigment that colours your skin, clump up instead of spreading out evenly. Most people will develop a few moles during the first 30 years of our lives, and this is especially likely if you are lighter-skinned. Moles can also occur due to natural hormonal changes within your body, particularly during your teenage years or if you are pregnant, but they may fade or disappear as you age.
A mole can develop into melanoma, a form of skin cancer that can spread to other parts of the body, if it is exposed to UV rays from the sun or tanning beds. The majority of moles will not develop into melanomas if you keep them safe, but it is important to monitor them monthly to pick up any signs that skin cancer may be developing before it becomes more serious. That said, it can be difficult to spot changes in a mole that you look at regularly, so you may find it useful to take photographs to compare the appearance of the mole over time. I always recommend checking moles and detecting changes using the ABCDE method. This comprises:
- Asymmetry– Ask yourself if the two halves of the mole look the same. The shape, colour or texture might be different
- Border – If the border is ragged, uneven or blurry this is abnormal
- Colour – You may notice that the mole is not a consistent colour throughout. It may have patches of different shades of pink, brown, black or purple
- Diameter– Moles that are bigger than 6mm across are at a higher risk of being cancerous
- Evolving – Any mole that grows or changes in appearance over weeks or months should be monitored closely. You should also watch for a mole becoming inflamed, or beginning to bleed, crust, or itch
Around 1 in 10 people will have a mole that has at least one of these abnormal characteristics, but only 1 in 10000 of these moles will turn out to be cancerous. Always err on the side of caution and if you have a change in your mole, then book an appointment with your dermatologist. He/she can examine your mole and determine if it needs further investigation such as a biopsy.
Skin damage, especially sunburn, from UV rays is the biggest avoidable risk factor for melanoma so to keep your moles healthy aim to avoid excessive sun exposure when you are outside and if you are outside ensure you wear sun protection with SPF rating of 30 or above.