A black spot on your skin is usually a harmless buildup of pigment caused by sun exposure, aging, or a past skin injury. The most common culprits are age spots (also called sunspots or liver spots), seborrheic keratoses, and dark marks left behind after acne or a rash. In rare cases, a black spot can be a sign of melanoma, a serious form of skin cancer that affects roughly 2.2 percent of people at some point in their lifetime. Knowing what different types of dark spots look like helps you figure out which ones to ignore and which ones deserve a closer look.
Age Spots From Sun Exposure
Age spots are the most common reason for dark patches on the skin. They’re flat, oval areas of increased pigmentation that range from tan to dark brown or even black. They typically show up on parts of the body that get the most sun over the years: the backs of your hands, your face, shoulders, upper back, and the tops of your feet. Most are about the size of a freckle, though they can grow to roughly half an inch across, and they often cluster together in groups that make them more noticeable.
These spots form when years of ultraviolet light cause your skin’s pigment-producing cells to go into overdrive. Melanin, the substance that gives skin its color, starts clumping together or getting produced in high concentrations in one area. A history of frequent sun exposure or sunburns raises your risk. Age spots are completely harmless on their own, but any spot that turns very dark, changes shape, or starts bleeding should be evaluated by a dermatologist, since those changes can sometimes overlap with melanoma.
Seborrheic Keratoses
Seborrheic keratoses are noncancerous growths that often get mistaken for something more serious because they can look dark and irregular. They range from light tan to brown to black, and their defining feature is a waxy, slightly raised texture that looks as if it was dripped onto the skin by a candle. Dermatologists sometimes describe them as having a “pasted on” appearance, because they sit on top of the skin rather than blending into it.
These growths are round or oval, can be very small or larger than an inch across, and tend to appear on the face, chest, shoulders, and back. They’re extremely common in middle-aged and older adults. While they don’t require treatment, they can be removed if they’re irritating or cosmetically bothersome.
Dark Marks After Skin Injury
Post-inflammatory hyperpigmentation is a flat, darkened patch that appears after your skin heals from some kind of inflammation or injury. Acne is one of the most common triggers, but sunburns, eczema flare-ups, cuts, and other rashes can all leave behind dark marks once the initial problem clears up. The skin in that area simply produces extra pigment during the healing process.
These spots are not scars, even though they can linger for months. They’re more common and more visible in people with darker skin tones, and sun exposure can make them last longer. Most fade on their own over time, though certain treatments can speed up the process.
How to Spot Something Dangerous
Most black spots on the skin are benign, but melanoma can disguise itself as a new or changing dark spot. The ABCDE rule, developed by the National Cancer Institute, is the standard checklist for identifying suspicious spots:
- Asymmetry: One half of the spot doesn’t match the other.
- Border: The edges are ragged, notched, or blurred instead of smooth.
- Color: The spot has uneven shading, with a mix of black, brown, tan, white, red, or blue areas.
- Diameter: The spot is larger than about a quarter inch (6 millimeters), though melanomas can be smaller.
- Evolving: The spot has changed in size, shape, or color over the past few weeks or months.
Beyond those visual clues, certain physical symptoms also raise a red flag. A spot that bleeds, crusts over, oozes, or won’t heal is worth getting checked. The same goes for a spot that itches persistently or feels tender without an obvious cause.
Black Spots on Palms, Soles, and Nails
A type of melanoma called acral lentiginous melanoma shows up in places most people don’t think to check: the soles of the feet, the palms of the hands, and under the fingernails or toenails. It appears as a black or brown discoloration that may look like a bruise or stain at first but grows in size over time.
This type occurs equally across all races and backgrounds, but it accounts for the majority of melanoma cases diagnosed in people of color. Under the nails, it typically appears as a dark vertical streak running the length of the nail bed. As it progresses, it can cause the nail to crack or break. Because these spots show up in areas that aren’t typically sun-exposed, they’re easy to overlook. Checking the bottoms of your feet and your nail beds periodically is worth the habit.
What Happens During a Skin Check
If a dermatologist wants a closer look at a suspicious spot, the next step is a skin biopsy. This is a quick, in-office procedure done under local anesthesia. The three main types differ in how deep they go.
A shave biopsy is the most common. Your doctor uses a thin blade to remove a sample from the top layer of skin, then applies pressure or a topical medication to stop the bleeding. No stitches needed. A punch biopsy uses a small circular tool (about the size of a pencil eraser) to take a slightly deeper sample, and may require a stitch or two. An excisional biopsy removes the entire suspicious area with a scalpel and is closed with stitches. Results typically come back within a week or two and tell you definitively whether the spot is benign or needs further treatment.
Treatments for Harmless Dark Spots
If your dark spot is benign but you want it gone, several options can fade or remove it depending on how deep the pigment sits.
Over-the-counter products work best for surface-level pigmentation like age spots and post-inflammatory marks. Look for ingredients like vitamin C, niacinamide, glycolic acid, azelaic acid, or kojic acid. These work by slowing pigment production or gently exfoliating the top layer of skin. Retinoids, available both over the counter and by prescription, are another effective option that speeds cell turnover so pigmented skin sheds faster.
For more stubborn spots, dermatologists can offer stronger interventions. Chemical peels use higher-concentration acids to remove the outer layer of skin, revealing less pigmented skin beneath. Microdermabrasion physically buffs away surface pigmentation with an abrasive tool. Laser treatments use targeted beams of light to break up pigment clusters. These range from gentler non-ablative lasers (which work beneath the surface without removing skin) to ablative lasers (which remove the outer layers entirely). Intense pulsed light therapy uses broad-spectrum light to address pigmentation across larger areas. Most of these treatments require multiple sessions, and your skin will be more sensitive to the sun afterward.
Preventing New Dark Spots
Since UV exposure is behind most benign dark spots and is a major risk factor for melanoma, sun protection is the single most effective prevention strategy. The American Academy of Dermatology recommends a broad-spectrum, water-resistant sunscreen with an SPF of at least 30 every time you go outside, even on cloudy days. Reapply every two hours, or immediately after swimming or sweating.
Most people use far less sunscreen than they need. A full-body application for an adult takes about one ounce, roughly the amount that fills a shot glass. For your face alone, use at least a teaspoon. Combining sunscreen with hats, sunglasses, and protective clothing gives you the best coverage, especially between 10 a.m. and 2 p.m. when UV rays are strongest. For dark spots you already have, consistent sun protection keeps them from getting darker and helps topical treatments work more effectively.