A common wart is a small, rough, raised bump on the skin, typically round or slightly irregular in shape, with a surface that looks and feels like a tiny piece of cauliflower. Most common warts range from about 2 millimeters to 10 millimeters wide, roughly the size of a pencil eraser or smaller. They can appear alone or in clusters, and they grow gradually over weeks or months before becoming noticeable.
Surface Texture and Shape
The most recognizable feature of a common wart is its rough, grainy surface. The outer layer of skin on a wart is thickened and hard, which gives it that bumpy, cauliflower-like texture when you run your finger over it. This sets warts apart from moles or other smooth skin growths. The borders are usually well-defined, meaning you can clearly see where the wart ends and normal skin begins.
Common warts are typically dome-shaped, rising above the surrounding skin. Some are more flat or irregular, depending on where they grow and how long they’ve been developing. Early on, a wart may be barely noticeable, looking like a small, slightly rough patch. Over time it becomes more raised and textured as the virus drives the skin cells to multiply faster than normal.
The Black Dots Inside
One of the most distinctive visual clues is a scattering of tiny black or dark red dots within the wart. These are often called “wart seeds,” but they aren’t seeds at all. They’re actually small blood vessels (capillaries) that have clotted inside the wart. The wart’s rapid growth traps these tiny vessels, cutting off their blood flow and turning them dark.
Not every wart has visible black dots on the surface. Sometimes they’re buried deeper and only become apparent if the top layer of the wart is scraped or filed down. When that happens, those exposed capillaries can cause tiny pinpoints of bleeding. If you see these dots in a rough bump on your skin, it’s a strong indicator you’re dealing with a wart rather than a callus or other growth.
Color
On lighter skin, common warts are usually skin-colored, grayish-white, or slightly yellowish-brown. On darker skin tones, warts may appear slightly lighter or darker than the surrounding skin, but they maintain the same rough texture and shape. The color alone isn’t always a reliable identifier since warts tend to blend with your natural skin tone. The texture and those telltale black dots are more useful visual markers.
Where They Usually Show Up
Common warts appear most often on the hands, particularly the backs of the fingers and around the fingernails. The knees and toes are also frequent locations. They favor areas where the skin is broken or frequently irritated, since the virus enters through tiny cuts or scrapes. Nail biters often develop warts around and under their fingernails, where the skin is constantly damaged.
Location can slightly change how a wart looks. A wart growing next to or under a fingernail (called a periungual wart) may distort the nail’s shape or lift it slightly. Warts on the knuckles or joints may appear more flattened because of repeated pressure and bending. On the soles of the feet, warts get pushed inward by body weight, making them look more like a thick callus than a raised bump.
How Warts Differ From Corns and Calluses
Since warts, corns, and calluses are all areas of thickened skin, it’s easy to confuse them. The key differences come down to a few details:
- Skin lines: A callus or corn preserves the natural lines and ridges of your skin across its surface. A wart disrupts those lines. If you look closely and the normal skin pattern seems to go around the bump rather than through it, that points toward a wart.
- Black dots: Corns and calluses don’t contain clotted blood vessels. If you see dark specks inside the growth, it’s likely a wart.
- Pain pattern: Corns hurt most when you press directly down on them. Plantar warts on the foot often hurt more when you squeeze them from the sides.
- Location logic: Corns and calluses form at pressure points, like where shoes rub. Warts can appear anywhere the virus has entered the skin, including spots with no obvious friction.
Other Wart Types That Look Different
Not all warts look like the classic rough bump. The virus that causes warts (HPV) has many strains, and some produce growths with a very different appearance. Flat warts are smoother and smaller, often appearing in clusters on the face or legs. Filiform warts grow in thin, thread-like projections that stick out from the skin, commonly around the eyes, nose, or mouth, and they tend to grow faster than common warts. Plantar warts on the feet grow flat and inward rather than outward because of the pressure from walking. When multiple plantar warts merge together, they form what’s called a mosaic wart, which can cover a larger area of the sole.
If what you’re looking at is smooth, has thread-like projections, or sits on the bottom of your foot, it may still be a wart, just a different variety than the classic common wart.