Skin Cancer Explained: Symptoms, Causes and Diagnosis

Female doctor diagnosing skin cancer on the body of a female patient

Skin cancer is one of the most common types of cancer in the UK, but it’s also one of the most treatable—if caught early. That’s why recognising the signs, understanding what causes it, and knowing when to see a doctor is absolutely crucial.

In this blog, we’ll walk you through everything you need to know about skin cancer symptoms, causes, diagnosis, and what you can do to stay one step ahead.

What Is Skin Cancer?

Skin cancer happens when the cells in your skin grow abnormally. Usually, this is caused by damage from ultraviolet (UV) light, either from the sun or tanning beds. Over time, that damage builds up and can lead to changes in your skin that turn cancerous.

There are three main types of skin cancer:

  • Basal cell carcinoma
  • Squamous cell carcinoma
  • Melanoma (the most serious and likely to spread)

Skin Cancer Symptoms: What to Look Out For

So, how can you detect skin cancer? The symptoms can vary depending on the type, but there are some key things to keep an eye on.

Common Signs Include

  • A new mole or growth that looks different to your others
  • A sore that doesn't heal after 4 weeks
  • A patch of skin that itches, bleeds, crusts over, or changes shape or colour
  • A lump that’s pink, shiny or red
  • Flat red or brown patches that may be rough or scaly
  • Cancerous skin tags – although most skin tags are harmless, in rare cases they can become cancerous. If they change colour, grow rapidly, or bleed, get them checked.

Does skin cancer itch?

Yes, sometimes it does. Itchiness, along with bleeding or pain, can be early warning signs—especially if they last longer than a few weeks.

What Causes Skin Cancer?

You might wonder, what causes skin cancer in the first place?

The most common causes include

  • Too much UV exposure from sunlight or sunbeds
  • Repeated sunburn, especially in childhood
  • Fair skin that burns easily
  • A weakened immune system
  • A family history of skin cancer
  • Certain medications or medical treatments (like UV therapy)

Not all cases are caused by sun exposure. Skin cancer can also develop in places that don’t see much sun, such as the genitals, soles of the feet, or under fingernails—especially in people with darker skin tones.

How Quickly Can Skin Cancer Grow or Spread?

How quickly can skin cancer grow?

Some types, like basal cell carcinoma, grow slowly over months or years.

How quickly can skin cancer spread?

Melanoma, however, can spread within weeks if left untreated. It’s why early detection is key—and why regular skin checks are so important.

Diagnosing Skin Cancer

When you visit your GP with a suspicious spot or mole, here’s what usually happens:

1. Visual Inspection

The doctor examines the skin growth using a dermatoscope (a specialised magnifying tool). They’ll ask about how long it’s been there, if it’s changed, and if you’ve noticed any symptoms like pain or itching.

2. Biopsy

If needed, a small sample of the skin is taken and sent to a lab for testing.

3. Further Testing

If the results show cancer, further scans or tests may be recommended to check if it’s spread.

Treatment Options

The good news is that most skin cancers can be completely removed, especially if caught early.

Treatments include:

  • Excisional surgery (cutting the cancer out)
  • Cryotherapy (freezing cancer cells)
  • Mohs surgery (precise removal of thin layers of skin)
  • Radiotherapy or chemotherapy for more advanced cases
  • Immunotherapy to help your body fight the cancer

Your treatment will depend on the type, location, and stage of your cancer.

Can You Die from Skin Cancer?

Unfortunately, yes. If left untreated, melanoma in particular can be fatal. But most cases of skin cancer are completely treatable when caught early.

That’s why we always advise checking your skin regularly and seeing a GP promptly if anything looks or feels odd.

FAQs About Skin Cancer Symptoms, Causes and Diagnosis

Can skin tags be cancerous?

Most skin tags are harmless, but in rare cases, they can develop into cancerous lesions. If a skin tag changes quickly, grows, or bleeds, get it checked.

Does skin cancer itch or hurt?

Yes. Skin cancer can itch, sting, or cause a burning sensation. It might also bleed or form a crust.

How can you detect skin cancer at home?

Look for any new or changing moles, lumps, or patches. Use the ABCDE rule:

  • Asymmetry
  • Border irregularities
  • Colour variation
  • Diameter >6mm
  • Evolving shape/size/feel

Take photos to track changes and use a mirror for hard-to-see areas—or ask a friend to help.

How do I get a diagnosis privately?

You can book a same-day consultation with one of our experienced Private GPs who can perform an initial assessment and arrange referrals if needed.

Check our Private GP Consultation Costs

Final Thoughts

Your skin is your body’s largest organ—and it deserves attention. Whether it’s an unusual mole, an itchy patch, or a sore that won’t heal, don’t ignore it. Early action saves lives.

If you’re worried about anything on your skin, we’re here to help.

Book an appointment at Private Medical Clinic

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