Skin cancer is the most common cancer in the United States, but it’s also one of the most treatable when caught early¹. The challenge is that many people ignore small changes in their skin, assuming they’re harmless.
Warning signs of skin cancer include moles with uneven shapes, jagged or blurred edges, spots with multiple colors, and any mark that changes size or appearance over time. Sores that won’t heal and new firm lumps are also potential red flags.
Recognizing these seven warning signs can make all the difference between early treatment and advanced cancer. Let’s explore what each sign looks like and when you need immediate medical attention.
The 7 Warning Signs of Skin Cancer
Not every spot or mole on your skin is dangerous. Many are harmless and stay the same throughout your life. The key is knowing which skin changes to watch for concern. Doctors often use the “ABCDE” rule to guide patients. Below are seven key warning signs of skin cancer to watch for:
1. Asymmetry/When One Side Doesn’t Match
A healthy mole is usually round or oval and looks the same on both sides. If one half of a mole looks different from the other, it could be a sign of melanoma, the most serious type of skin cancer.
2. Border Irregularity/jagged or Blurred Edges
Moles or spots with smooth, even borders are usually safe. If the edges look uneven, rough, notched, or fade into the skin, it’s worth getting them checked.
3. Color
Normal spots are usually just one shade of brown. A warning sign is when a mole or patch of skin has multiple colors, such as different shades of brown, black, red, pink, or even blue.
4. Diameter Larger Than a Pencil Eraser
Any spot larger than 6 millimetres should be taken seriously, especially if it continues to grow.
5. Evolving Spot Over Time
The most important sign is change. If a mole or mark looks different from before, whether it’s getting larger, darker, raised, itchy, or starts bleeding. That’s a red flag.
6. Firm or Fast-Growing Lumps
Some skin cancers, like nodular melanoma, appear as firm bumps that grow quickly over weeks. These require urgent medical attention because they spread more rapidly than most other types.
7. Sores or Patches That Don’t Heal
A sore that keeps bleeding, scabbing, or refuses to heal is not normal. Likewise, a scaly patch or a scar-like area that appears without injury may be a sign of basal or squamous cell skin cancer.
Why Early Detection of Skin Cancer Matters
Catching skin cancer symptoms early can make the difference between a simple treatment and a life-threatening condition. When spotted in its earliest stages, most types of skin cancer can be removed quickly and effectively, often with minor procedures. But if it’s ignored, the tumour can spread deeper into the skin or to other parts of the body, making treatment more complex and risky.
Some skin changes just can’t wait for your next routine check-up. If a mole starts bleeding, a sore refuses to heal, or a spot grows rapidly within weeks, these are red flags that need urgent attention. Acting fast not only improves your chances of recovery but can also prevent long-term complications.
When Skin Cancer Symptoms Require Emergency Care
Most skin changes can be checked during a regular doctor’s visit, but some warning signs need urgent attention. If you notice any of the following, don’t wait for a routine appointment; seek emergency care right away:
- Bleeding that doesn’t stop – a mole or sore that bleeds repeatedly or oozes without healing.
- Severe or increasing pain – skin cancer is often painless, so new or worsening pain can signal something serious.
- Rapid growth within weeks – any lump, mole, or spot that seems to be doubling in size quickly.
- Sores in sensitive areas – suspicious spots near the eyes, nose, lips, genitals, or under the nails.
- Sudden or dramatic change – a mole or patch that looks very different from all your other spots.
How to Monitor Your Skin for Changes
Paying attention to your skin is one of the simplest and most powerful steps you can take for your health. Make a habit of checking your skin from head to toe once a month, including less obvious places like your scalp, back, under your nails, and the soles of your feet. If you notice any warning signs of skin cancer, write down when you first observed the change and keep track of its appearance over time. Early detection through regular monitoring can be lifesaving.
Conclusion
Skin cancer is common, but it doesn’t have to be deadly if it’s caught early. Learning to spot the seven warning signs, whether it’s a mole that changes shape, a sore that won’t heal, or a lump that grows quickly, gives you the power to act before it spreads.
Most skin changes are harmless, but it’s always better to be safe than sorry. Keep a close eye on your skin, schedule regular check-ups, and don’t ignore anything that feels unusual. And if you notice urgent red flags like bleeding, sudden pain, or rapid growth, the emergency room is the right place to go.
Frequently Asked Questions
1. Does every mole or skin spot mean cancer?
No, most moles and spots are harmless. The concern arises when a mole looks different from your other spots, changes over time, or exhibits warning signs such as bleeding, itching, or uneven colour. Those are the ones that need medical attention.
2. How often should I check my skin for changes?
Doctors recommend doing a full skin self-check once a month. Use a mirror to inspect hard-to-see areas and ask a family member for assistance if needed. Regular checks make it easier to notice new or unusual changes early.
3. Should I go to the ER for every suspicious mole?
No, any changes can be reviewed during a regular doctor’s visit. But if a spot is bleeding, painful, rapidly growing, or looks dramatically different, don’t wait. Head to the ER for immediate care.
