Subungual Melanoma vs Subungual Hematoma

Melanoma of the nail unit is a potentially serious cancer that may resemble a bruise. A collection of blood beneath a nail after injury or repeated pressure.

Research updated 2026-10-23

Key differences What is it?What it looks like Diagrams When it starts Triggers Daily Care Treatment Outlook Complications When to get help Questions

Key differences

The same eight facts on every condition comparison.

Usual age

50 and over

Any age

Where

Thumb or big toe nail

Fingernails or toenails

Main sign

Dark nail streak that widens

Dark red to black under the nail

Itch or pain

Usually painless

Throbbing at first

Contagious

Long term

Serious if not treated early

Grows out over months

Scars

After surgery

Who gets it

Adults; all skin tones

Anyone after an injury; runners

What is it?

Subungual Melanoma

Subungual Hematoma

What is it?

What it is
Melanoma of the nail unit is a potentially serious cancer that may resemble a bruise.

What it is
A collection of blood beneath a nail after injury or repeated pressure.

What it looks like

Subungual Melanoma

A fingernail with a dark longitudinal band extending onto the skin near the nail base, beside an examination light.

Subungual Melanoma A broad brown-black stripe extends lengthwise through the nail.

Subungual Hematoma

A big toe with a dark purple patch beneath the nail plate.

Subungual Hematoma A purple-black patch is visible under part of the large toenail.

Skin tones

Subungual Hematoma, representative educational image.

In the skin

Malignant pigment cells multiply within the nail unit. Their growth can affect the nail plate, nearby tissue or the pigment visible through the nail.

Impact or repeated pressure damages small blood vessels beneath the nail. Blood collects between the nail plate and its bed, creating a dark patch that can be painful.

When it usually starts

010203040506070+

Subungual Melanoma. Usually diagnosed in adults, but an unexplained changing nail lesion needs assessment at any age.

Subungual Hematoma. Can occur at any age after injury.

Causes and triggers

Causes

Malignant pigment cells grow within the nail unit.

Impact, pressure or repetitive injury damages the nail unit.

Risk factors

Personal or family melanoma history, Unexplained changing nail lesion

Crush injury, Tight footwear, Repeated sports pressure

Trigger

● Subungual Melanoma

● Subungual Hematoma

No established short-term flare trigger

Not a typical trigger

Not listed

Trauma

Not listed

Can contribute

Repeated shoe pressure

Not listed

Can contribute

Daily Care

Subungual Melanoma

Subungual Hematoma

Daily care

Habits that help

Arrange prompt professional assessment
A suspicious skin or nail change cannot be safely diagnosed or treated through home care.
Take a clear dated photograph without delaying the appointment
Record when the change appeared and whether it is growing or bleeding.
Protect the area from repeated injury
Use a clean dressing if needed for a fragile or bleeding surface.
Keep recommended biopsy and follow-up appointments
Diagnosis and treatment depend on examination and, when indicated, tissue testing.
Remove nail polish before the nail assessment
Tell the clinician about a new dark band, pigment spreading onto nearby skin or a changing nail.
Discuss cancer treatment planning
Confirmed melanoma needs stage-appropriate specialist management.

Avoid

Avoid: Burning, freezing, cutting or applying acids at home
Destroying the surface can delay diagnosis and damage tissue needed for testing.
Avoid: Waiting for pain before seeking help
Melanoma and other skin cancers can be painless.

Habits that help

Protect the nail from further knocks and pressure
Use roomy footwear for an injured toenail and avoid activities that keep striking it.
Keep broken skin gently clean and covered
Follow any dressing instructions after nail-bed repair or drainage.
Raise the injured hand or foot if swollen
A wrapped cool pack may help after a recent injury; avoid direct ice on skin.
Allow the nail to grow out without pulling it off
Trim only a loose free edge if it catches, and leave attached nail in place.
Arrange review for unexplained or persistent nail pigment
Do not assume every dark nail is a bruise, especially without a clear injury.
Protection and pain relief
Protect the nail and use suitable labelled pain relief if needed.
Discuss nail-bed and pressure assessment
Severe pressure pain, a crush injury or an open wound may need drainage, repair or imaging by a clinician.

Avoid

Avoid: Drilling, burning or piercing the nail yourself
Severe pressure pain or a significant crush injury may need prompt professional care.

Treatment differences

Evidence labels come from each condition’s own treatment list.

Treatment

● Subungual Melanoma

● Subungual Hematoma

Treatment approach

—

Protect a mildly injured nail and use suitable pain relief if needed. Severe pressure pain, a crush injury or an open wound may need prompt professional assessment; do not drill or burn a hole in the nail yourself.

Procedures

Nail-unit biopsy

Listed

A specialist determines how to obtain a diagnostic sample; cosmetics or antifungals must not delay assessment.

None listed

Outlook

Long term

The outlook depends on the cancer's thickness and stage when diagnosed. Prompt assessment and appropriate treatment matter; an unexplained changing nail band should not be watched indefinitely as a presumed bruise.

The dark area should gradually move toward the nail tip as the nail grows. This takes months and is slower in toenails; unexplained pigment or pigment that does not grow out needs assessment.