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Blood Blister vs Melanoma - How to Tell Them Apart

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At a glance, it can be difficult to know the difference between a harmless blood blister and a potentially life-threatening melanoma.

In this article, we’ll discuss blood blisters and melanomas, equipping you with the knowledge to distinguish between the two, understand the warning signs, and take proactive steps to ensure healthy skin.

melanoma v's blood blister

What is a blood blister?

A blood blister is a common skin condition that’s characterised by a small pocket of blood that forms between the layers of the skin.

It typically occurs as a result of minor trauma or friction, such as pinching, rubbing, or excessive pressure on the skin. They usually appear as round or oval-shaped blisters with a dark red or purple colour and a translucent appearance.

While they can be uncomfortable and tender, blood blisters are generally harmless and tend to heal on their own within a few days or weeks.

What is melanoma?

Melanoma spot on skin

Melanoma is a type of skin cancer that develops from the cells responsible for producing melanin – the pigment that gives colour to the skin, hair, and eyes.

It is a serious and potentially life-threatening disease, often appearing as an abnormal mole or spot on the skin. Warning signs include asymmetry, irregular borders, colour variation, and changing characteristics over time.

Melanoma can occur anywhere on the body, even in areas not exposed to the sun. Early detection, diagnosis, and appropriate treatment is crucial for managing melanoma.

Nodular melanoma can be mistaken for a blood blister

Nodular melanoma is a particularly aggressive form of melanoma that can sometimes be mistaken for a blood blister.

This type of melanoma often presents as a raised bump or nodule on the skin, similar to the appearance of a blood blister. In saying that, there are important distinctions to make note of.

Unlike blood blisters, nodular melanomas tend to have a uniform colour – often dark brown or black – and lack the translucent appearance of a blood blister.

Nodular melanomas also tend to grow rapidly, and the surrounding skin may exhibit signs of redness or swelling.

It is crucial to seek medical evaluation and not dismiss a suspicious bump. This ensures early detection and appropriate treatment if it is, in fact, a nodular melanoma.

Blood blister vs melanoma – Similarities & differences

While blood blisters and melanomas may share certain visual similarities, it’s important to recognise the distinct characteristics that set them apart.

Let’s explore the similarities and differences between these two skin conditions. By understanding these nuances, you can be prepared for timely recognition, proper diagnosis, and appropriate medical attention, when necessary.


  • Can both appear as raised bumps or lesions on the skin.
  • May both be initially noticed as spots resembling blisters.
  • Can appear on various parts of the body (although blood blisters are often found in areas prone to friction).


  • Blood blisters are a result of minor trauma or friction, whereas melanomas arise from malignant cells in the skin.
  • Melanomas often appear as abnormal moles or spots, while blood blisters typically have a round or oval shape, dark red or purple colour, and a translucent appearance.
  • While blood blisters generally heal on their own within a few days or weeks, melanomas evolve over time and will not go away without treatment.
  • Blood blisters are usually harmless and do not pose a significant health risk, but melanomas require prompt medical attention to avoid any serious progression of the skin cancer.

What to do if you suspect melanoma

If you suspect melanoma or notice any concerning changes in your skin, it is crucial to take action as quickly as possible.

The ABCDE method is a useful tool for evaluating suspicious moles or spots on the skin. Here’s how it works:

Image Source: ocskincancer.com

A - Asymmetry

Check if one half of the mole or spot matches the other half. Melanomas often exhibit asymmetrical shapes, unlike benign moles, which are typically symmetrical.

B - Border Irregularity

Examine the edges of the mole or spot. Melanomas may have irregular, jagged, or poorly defined borders, while benign moles tend to have smooth or even borders.

C - Colour Variation

Note any variations in colour within the mole or spot. Melanomas may display different shades of brown, black, red, blue, or white. Benign moles, on the other hand, usually have a more uniform colour.

D - Diameter

Consider the size of the mole or spot. While melanomas can be smaller, they often exceed the size of a rubber pencil tip when diagnosed. Of course, it is still important to remember that smaller melanomas can still be dangerous.

E - Evolution or Change

Pay attention to any changes in the size, shape, colour, or elevation of a mole or spot over time. Melanomas often evolve and exhibit noticeable changes, unlike stable, benign moles.

If you notice any of these warning signs or have concerns about a particular spot on your skin, it is essential to seek a professional skin check by a healthcare provider.

A doctor experienced in skin conditions can perform a thorough examination of your skin, assess the suspicious area, and, if needed, recommend further diagnostic tests or a biopsy for accurate diagnosis.

Getting a skin check

It’s very important to get regular skin checks, especially if you have a family history of melanoma or other risk factors, such as:

  • Excessive sun exposure
  • Older age
  • Previous melanoma history
  • Numerous moles or atypical moles.

Remember, detecting melanoma early greatly increases the chances of successful treatment and improved outcomes. Don’t hesitate to schedule a skin check and prioritise your skin health.

Safeguarding your skin: Awareness and action

If you suspect melanoma or notice any concerning changes in your skin, seeking a professional skin check is crucial for accurate diagnosis and appropriate treatment.

Prioritise your skin health, practise sun safety measures, and don’t hesitate to consult with healthcare professionals when needed. Your vigilance and action can make a significant difference in safeguarding your skin and overall wellbeing.

Visit the skin cancer professionals at SunDoctors

Skin doctor chatting to client in office

The team at SunDoctors skin cancer clinics take great pride in educating the community about skin cancers and skin cancer prevention. SunDoctors is a leading provider of skin cancer prevention, diagnosis, treatment, and education. With clinics operating in over 40 locations across Queensland, New South Wales, Victoria, and South Australia, SunDoctors patients are guaranteed a rapid diagnosis, pathology, and referral.

If you want more information or have any questions, want to learn more about melanoma checks and self-examinations, or if you're looking to book a skin cancer check, call 137546 (13SKIN) or book online at sundoctors.com.au.

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