Why changing spots matter
Most moles are harmless. Nearly everyone has some, and they usually appear in childhood and early adulthood. What matters is not simply having moles but whether a spot is new, different from your others, or changing. Skin cancers, including melanoma, can begin as a new spot or as a change in an existing mole. Many changes turn out to be benign, but it is not possible to tell by eye alone, and the stakes of a missed problem are high enough that a professional look is the sensible response to a changing spot.
Nothing in this article can tell you whether a particular mole is safe. Only a trained clinician can evaluate that, sometimes with specialized tools or a small sample sent for testing.
A simple way to check your own skin
Regular skin checks at home are a general habit many health organizations encourage. There is no single perfect schedule. Many people choose roughly once a month or every few months, whichever they will actually keep up.
- Use good light and a full-length mirror, plus a hand mirror for the back and other hard-to-see areas.
- Work in order. Start with the face, scalp (part the hair), ears and neck, then the chest, arms, hands, between fingers and under nails, then the torso, legs, feet, soles and between toes.
- Look in less obvious places. Skin cancers can occur in areas that rarely see the sun, including the soles, nails and genital area.
- Ask for help with your back or scalp from a partner or friend, or take photos.
- Record what you see. Dated photos taken in similar light, perhaps with a ruler or coin beside the spot, make comparing over time much more reliable than memory.
What to look for
A commonly taught guide is the “ABCDE” checklist. It is a prompt for attention, not a diagnosis.
- Asymmetry: one half does not match the other.
- Border: edges look ragged, notched or blurred.
- Color: uneven shades, such as tan, brown, black, and sometimes red, white or blue.
- Diameter: larger than about a pencil eraser is a traditional rule of thumb, though melanomas can be smaller.
- Evolving: any change in size, shape, color, height or how it feels.
Evolving is often considered the most important. A spot that is different from the rest, sometimes called the “ugly duckling,” is also worth pointing out. Because moles on different parts of the body vary, comparing a spot with your other moles is more informative than comparing it with a picture.
Other changes worth mentioning
Not every concerning spot is a dark mole. Mention these to a professional too:
- A sore that does not heal after several weeks, or that bleeds and crusts repeatedly
- A new pink, red or pearly bump that persists
- A rough, scaly patch that does not go away
- Itching, tenderness, pain or oozing from a mole
- A dark streak under a nail that you cannot explain by injury
- A spot that looks quite unlike anything else on your skin
Tiny new spots that appear after a breakout are usually something else, such as post-inflammatory marks. Dark marks left behind by pimples or irritation are common and usually fade, which falls under hyperpigmentation. A spot that stays and keeps changing is a different matter.
Who might need closer attention
Certain factors are generally associated with a higher chance of skin cancer, including a history of sunburns, many moles, fair skin that burns easily, a personal or family history of skin cancer, a weakened immune system, and extended sun exposure. However, skin cancers can occur in people of any skin tone, and in people with deeper skin tones they may be diagnosed later and in less sun-exposed locations such as palms, soles and nails. Everyone benefits from paying attention to their skin.
What happens at an appointment
A primary care doctor or dermatologist will look at the spot, often with a handheld magnifier. If it is concerning, they may remove it or take a small sample for examination under a microscope. This is quick and usually done with local numbing. Many referrals end with reassurance. You can also ask whether a full-body examination makes sense for you and how often to repeat it.
Everyday protection
Checking is about spotting problems; reducing risk is about limiting ultraviolet exposure. Sunscreen is one tool, alongside shade, hats and protective clothing. Repeated sunburn is considered a risk factor, so sunburn care and prevention are worth taking seriously. Sunscreen reduces risk but does not remove it, so it does not replace regular checks.
When not to wait
Do not wait for a change to hurt before getting it looked at. Early skin cancers are often painless. Book a visit promptly if a spot fits any of the changes above. Get seen urgently if a lesion is bleeding, rapidly growing or ulcerating. When you are unsure, asking is reasonable. Clinicians would rather examine a harmless spot than miss a serious one, and noting what you saw and when helps them considerably.