You notice a dark spot beneath your toenail. Maybe you bumped it, wore shoes that were too tight, or spent the weekend doing a little more walking than usual.
It’s probably just a bruise, right?
Sometimes, that’s exactly what it is. Toenails can become discolored from injuries, repetitive pressure, fungal infections, and other common conditions.
But not every dark spot is a bruise.
Melanoma, a serious form of skin cancer, can develop beneath your toenails and on areas of your feet you rarely think to examine.
The important thing isn’t to assume that every dark spot is dangerous. It’s to recognize when a change deserves a closer look.
Here’s what to watch for—and why checking your feet should be part of your regular skin care routine.
1. Can You Really Get Melanoma on Your Feet?
Yes. Although most people associate skin cancer with sun exposure, melanoma can develop in places that rarely see sunlight.
That includes:
- The bottoms of your feet
- Your heels and toes
- The skin between your toes
- Beneath or around your toenails
One type, called acral lentiginous melanoma, commonly develops on the palms, soles, or around the nails.
Melanoma on the feet can affect people of every skin tone. For people with darker skin, it’s particularly important not to overlook these less sun-exposed areas.
Because we don’t regularly inspect the bottoms of our feet or look closely at our toenails, changes in these areas may go unnoticed.
And that’s why a simple foot check matters.
2. What Does Melanoma Under a Toenail Look Like?
One possible sign of nail melanoma is a brown or black vertical streak running from the base of the nail toward the tip.
It may begin as a thin line or appear as a wider band of color.
But a dark streak doesn’t automatically mean cancer. Some people naturally develop harmless nail pigmentation, and injuries or certain medical conditions can also change nail color.
What matters is recognizing changes that should be evaluated.
Five Nail Changes You Shouldn’t Ignore
- A new or changing dark streak
A brown or black line that appears without an obvious explanation, particularly if it grows wider or becomes irregular.
- Color spreading onto the surrounding skin
Dark pigmentation that extends from the nail onto the cuticle or skin beside it.
- Unexplained nail splitting or lifting
A nail that begins to split, separate from the nail bed, or change shape without a clear cause.
- A new bump beneath the nail
A growth under the nail, especially one that enlarges, bleeds, or causes the nail to become distorted.
- A dark area that doesn’t behave like a bruise
Pigmentation that persists, changes, or doesn’t move outward as the nail grows.
Not all nail melanomas are dark. Some can appear pink, red, or relatively colorless, so an unexplained growth or persistent nail change also deserves attention.
These changes are warning signs, not a diagnosis. A dermatologist can determine whether further testing is needed.
3. Bruised Toenail vs. Melanoma: How Can You Tell the Difference?
Imagine noticing a dark area under your big toenail after a long hike.
You remember your shoe rubbing against your toe, and the nail feels tender.
That could be a bruise, also called a subungual hematoma, which occurs when blood collects beneath the nail.
But what if you don’t remember an injury? What if the dark area begins as a thin line, slowly widens, or changes over time?
Those details matter.
What a Typical Toenail Bruise May Look Like
A bruise beneath the nail often follows an injury or repeated pressure from footwear.
The discoloration may appear red, purple, brown, or black. As the nail grows, the dark area typically moves toward the tip, with normal-looking nail gradually appearing near the base.
Toenails grow slowly, so it can take many months for a bruise to grow out completely.
What Deserves a Closer Look?
A new or changing dark streak, pigmentation that becomes wider or more irregular, or discoloration that extends onto the surrounding skin should be evaluated.
An unexplained area of pigmentation that persists or changes rather than growing outward like a typical bruise also warrants attention.
You cannot reliably distinguish a bruise from melanoma based on appearance alone.
A bruise can occur without a remembered injury, and melanoma can sometimes resemble bleeding beneath the nail.
If you notice a new or changing dark streak, unexplained pigmentation, or another suspicious nail change, arrange a prompt evaluation with a dermatologist rather than waiting months to see what happens.
4. Don’t Forget to Check the Bottom of Your Feet
Your toenails aren’t the only places where melanoma can hide.
A dark spot on your heel might look like a bruise. A growth on the bottom of your foot might resemble a wart. An unusual area of thickened skin might be mistaken for a callus.
Sometimes, melanoma doesn’t even look dark. It may appear pink, red, or similar to your natural skin color.
Watch for:
- A new or changing spot on your sole, heel, or toes.
- A mole or patch that changes in size, shape, or color.
- An unusual growth that resembles a wart or callus.
- A sore that doesn’t heal or repeatedly heals and returns.
- A spot that bleeds, itches, or becomes painful.
One important point: melanoma doesn’t always hurt.
You may feel perfectly fine while a suspicious spot changes.
Rather than judging a spot by how much it bothers you, pay attention to whether it’s new, unusual, or evolving.
5. Remember the ABCDEs of Melanoma
You may have heard of the ABCDE rule for identifying potentially suspicious moles.
It’s a helpful tool for examining your feet, too.
A — Asymmetry
One half of the spot looks different from the other.
B — Border
The edges appear uneven, irregular, or poorly defined.
C — Color
The spot contains varying shades or develops a new color.
D — Diameter
A spot larger than a pencil eraser deserves attention, but melanoma can be smaller.
E — Evolving
The spot changes in size, shape, color, or appearance over time.
Of these warning signs, Evolving is especially important.
If a spot looks different than it used to, or doesn’t resemble the other spots on your skin, have it examined.
The ABCDE rule doesn’t identify every melanoma, particularly those that develop around or beneath the nails. A new nail streak, unexplained growth, or non-healing sore can warrant evaluation even if it doesn’t fit the ABCDE pattern.
6. The 30-Second Foot Check
Most of us would notice a new spot on our face or arms.
But when was the last time you examined the bottom of your heel?
Make checking your feet part of your monthly routine. It takes very little time, and becoming familiar with what’s normal for your feet makes unusual changes easier to recognize.
Your Five-Step Foot Check
Step 1: Look at the tops of your feet.
Check for new spots, changes in color, or unusual growths.
Step 2: Check between your toes.
Look for new marks, discoloration, or areas that won’t heal.
Step 3: Inspect every toenail.
Pay attention to new dark streaks, unusual pigmentation, or changes in nail shape.
Step 4: Look at your soles and heels.
Check for changing spots, unexplained growths, or non-healing sores.
Step 5: Use a mirror if needed.
Get a clear view of hard-to-see areas, or ask someone to help.
If you discover something unusual, you can take a clear photograph and note when you first noticed it. This can help you explain the change to your doctor.
However, a photograph or online comparison cannot rule out melanoma, and a suspicious finding shouldn’t be monitored at home instead of receiving a medical evaluation.
7. What Happens if You Find Something Suspicious?
First, don’t panic.
Many toenail and skin changes have causes other than cancer. Dark nails can result from injuries or harmless pigmentation, while unusual skin spots can have several possible explanations.
But guessing isn’t the answer.
A dermatologist can examine the suspicious area, often using a special magnifying instrument to evaluate details that aren’t visible to the naked eye.
If the finding is concerning, a biopsy may be recommended. This involves taking a tissue sample that can be examined under a microscope.
A biopsy is the way to determine whether a suspicious lesion is melanoma. Appearance alone, even in a photograph, cannot confirm or exclude the diagnosis.
If a podiatrist or Medical Nail Technician notices a suspicious lesion during a foot examination, they can help coordinate appropriate evaluation and referral.
The important thing is not to delay getting an unexplained or changing spot checked.
Your Feet Deserve a Skin Check, Too
We spend a lot of time thinking about foot pain, shoe comfort, and keeping our toenails looking their best.
But the skin on your feet deserves just as much attention.
A dark spot may be nothing more than an old bruise. A streak beneath your toenail may have a harmless explanation.
And a changing spot may be the first sign that something needs medical attention.
You don’t need to become an expert at identifying skin cancer. You simply need to become familiar with your feet and recognize when something looks different.
If you notice an unusual change, don’t just cover it with polish and forget about it. Have it evaluated.
Have You Noticed an Unusual Spot on Your Foot or Toenail?
At Feet for Life Podiatry Centers and CleanSpa, we encourage patients to take changes in their foot health seriously.
Our podiatrists and Medical Nail Technicians can evaluate foot and nail concerns and help coordinate further care when needed.
If you notice a suspicious new or changing pigmented spot, arrange a prompt appointment with a board-certified dermatologist for a skin cancer evaluation.
Questions About Your Foot or Toenail Health?
Visit feet for life for help with your foot and nail concerns.
