Warts: The Complete Guide to Types, Causes, and Treatment

You found a rough, raised bump on your finger, your foot, or the back of your hand. It is firm. It might have tiny dark dots in it. It was not there a few months ago, and now it is, and maybe a second one has appeared nearby. Most likely, this is a wart.

Warts are one of the most common skin growths in the world. They are caused by a virus, they are usually harmless, and most of them can be treated. This guide walks through what warts are, the subtypes that look and behave differently, why they show up, the few situations that genuinely need a doctor, and what your options are if you want one gone.

What are warts?

A wart is a small, rough growth caused by an infection of the top layer of skin with the human papillomavirus (HPV). The virus tells skin cells to multiply faster than normal, and the result is a thickened, raised bump. According to NIH MedlinePlus, warts are common and usually harmless, and many eventually go away on their own, though that can take months or years.

A typical wart is firm to the touch, rough or grainy on the surface, and the same color as your skin or slightly darker. Many warts have tiny black dots inside them. Those dots are small clotted blood vessels, not seeds, despite the common nickname. The dots are one of the most reliable signs that a bump is a wart and not something else.

What warts look like

Warts vary by where they grow and which strain of HPV caused them. Some are dome-shaped and raised, some are flat and barely textured, and some are long and thread-like. They can appear alone or in clusters. They do not usually hurt, with one important exception: a wart on the sole of the foot can be pressed flat by your body weight and become painful to stand on.

Types of warts

Knowing the subtype matters, because the subtype drives which treatment fits. Here are the common ones.

Common warts

Common warts are the dome-shaped, rough bumps most people picture. They grow most often on the hands, fingers, and around the nails, and they have the classic grainy surface with black dots. They are the most frequently treated subtype at home.

Plantar warts

Plantar warts grow on the soles of the feet. Because you walk on them, they get pushed inward and flat, and they can develop a hard, callused ring around a central core. They are often the most stubborn and the most uncomfortable subtype. For a detailed subtype breakdown, see our guide on plantar vs common vs flat warts.

Flat warts

Flat warts are smaller, smoother, and flatter than common warts. They tend to appear in large numbers, often on the face, the backs of the hands, or the legs. Because they are subtle, people often have dozens before noticing.

Filiform warts

Filiform warts are long, narrow, finger-like projections. They show up around the mouth, nose, and eyes, and they grow quickly. Their thread-like shape makes them easy to identify and, because they sit on a narrow stalk, often well suited to precise at-home treatment.

Periungual warts

Periungual warts grow around and under the fingernails and toenails. They can be painful, can distort nail growth, and are harder to reach, which makes them one of the trickier subtypes to treat at home.

Are warts dangerous?

For the large majority of people, no. The common warts on hands and feet are benign. They are a cosmetic and comfort concern, not a health threat, and the American Academy of Dermatology classifies them as harmless skin growths. There are real exceptions, and they matter.

Genital warts are different

Genital warts are caused by specific strains of HPV and are a sexually transmitted infection. They are not the same as the common warts covered in this guide, they should never be treated with at-home devices or over-the-counter wart products meant for hands and feet, and they require a doctor. If a growth is in the genital area, stop and see a healthcare provider.

When a bump is not actually a wart

Skin cancer can occasionally resemble a wart. If a growth bleeds without being touched, grows quickly, changes color, develops irregular borders, or simply does not look like a typical wart, do not treat it at home. See a dermatologist. The same applies to any growth you are not sure about. Resources at Mayo Clinic are a useful starting point for understanding when a growth needs professional review.

Warts or something else?

Several common skin growths get confused with warts. Here is how each one differs.

Wart vs skin tag

A skin tag is soft, smooth, and hangs off the skin on a thin stalk, often in skin folds like the neck, armpits, and groin. A wart is firm, rough, and sits flush on the skin, usually with black dots. Skin tags are not viral and are not contagious. For the full side-by-side, see our skin tags guide.

Wart vs mole

A mole is a flat or slightly raised brown or black spot made of pigment cells, usually smooth and present for years. A wart is rough, often skin-colored, and caused by a virus. Moles should never be treated at home, because mole changes can signal melanoma. If you are unsure whether a growth is a wart or a mole, see our moles guide and, when in doubt, a dermatologist.

Wart vs corn or callus

A corn or callus is thickened skin from pressure or friction, common on the feet. The key tell: a callus has continuous skin lines running across it, while a plantar wart interrupts those lines and often has the tiny black dots. A callus is not contagious; a plantar wart is.

What causes warts?

Warts are caused by HPV entering the skin, usually through a small cut, scrape, or area of softened skin. The virus is extremely common, and exposure does not guarantee a wart: whether you develop one depends heavily on your immune system.

How the virus spreads

HPV that causes common warts spreads through direct skin contact and through contact with surfaces a wart has touched, such as shared towels, locker-room floors, and pool decks. Touching one of your own warts and then another part of your body can spread it to yourself, which is why warts sometimes appear in a line or cluster. For the full breakdown of spread and prevention, see our guide on whether warts are contagious.

Why some people get warts and others do not

The immune system is the deciding factor. A healthy immune system often clears HPV before a wart ever forms, or clears an existing wart over time. People whose immune response is weaker tend to get more warts and keep them longer.

Warts in children and on the immune-compromised

Children and teenagers get warts far more often than adults, because their immune systems have not yet built up resistance to the common HPV strains and because they share equipment and close contact. People who are immunosuppressed, including those on certain medications or after organ transplant, also develop warts more frequently and more persistently. This is a documented pattern, not a theory.

Did you cause this? No.

You did not get a wart because you were unclean. Warts are a viral infection that anyone can pick up from ordinary contact, and getting one is not a sign you did anything wrong. The realistic goals are to treat the ones you have and to avoid spreading them.

Where warts fit: the viral and benign skin growth family

Warts belong to a broader group of common skin growths people deal with at home, which includes warts, skin tags (acrochordons), seborrheic keratoses, and moles (nevi), among others. Warts are the viral member of that group.

Knowing the category matters for one practical reason. The growths look similar from a distance but have very different causes and very different treatment rules. A method that suits a wart may be wrong for a mole, and a mole should never be self-treated at all. This is why identification comes first and treatment second.

Identify the subtype first. The subtype, not the bump, decides which treatment will actually work.

Treatment options

There is a clinical path and an at-home path. Both work for the right person and the right subtype.

Clinical treatment

Dermatologists treat warts with several options, each suited to different cases:

• Cryotherapy. Liquid nitrogen freezes the wart. Effective, especially for plantar warts, and usually needs several sessions.
• Cantharidin or stronger acids. An in-office application that blisters the wart so it lifts away.
• Electrosurgery and curettage. The wart is burned and scraped off. Good for stubborn single warts.
• Laser treatment. Reserved for warts that resist other methods or that are numerous.
• Immunotherapy. For widespread or resistant warts, the doctor stimulates the immune system to attack the virus.

Costs add up per session and per wart, which is why people with one or a few accessible warts often look at home first.

At-home treatment

For common, flat, and filiform warts in safe locations (not genital, not on the face near the eyes without care, not a growth you are unsure about), at-home treatment is a reasonable first step. Over-the-counter salicylic acid is the traditional route and works slowly over weeks. Cryotherapy kits freeze the wart but can be hard to aim and can damage surrounding skin. The more precise at-home approach is to direct energy to the wart tissue itself so it is treated at the source and the skin renews on its own.

The OcuraLife Plasma Pen is the at-home device built for precise treatment of this category of growth. It delivers plasma energy at low power directly to the wart, so the raised tissue is treated without spreading across healthy skin, and it runs at 9 power settings so you can match intensity to the subtype and location (a filiform wart on a stalk tolerates different settings than a thick common wart). For the full method walkthrough, see our warts removal at home guide, and for the buyer-side method comparison see best at-home wart removal.

A note on subtype fit. Plantar warts, pressed deep into the sole, are the one subtype where cryotherapy often has the edge, and very stubborn plantar warts are worth a doctor visit. Common, flat, and filiform warts in reachable spots are where precise at-home treatment shines.

What to expect from at-home plasma pen treatment

Aftercare is simple: keep the area clean and dry, do not pick the scab, and protect the spot from the sun while it heals. Picking is the most reliable way to leave a mark and to risk spreading the virus, so leave it alone.

When to see a dermatologist instead

Skip at-home treatment and see a dermatologist if any of the following is true.

There is no downside to having a dermatologist confirm what something is. The at-home option is for the ordinary warts you already recognize. Anything ambiguous deserves a professional eye first.

FAQ

Frequently asked questions

Quick answers

The questions readers ask most about warts, answered directly.

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The bottom line

Warts are common, viral, and for most people harmless. The rough bump you found is your skin reacting to HPV, not a sign you did anything wrong. The two things worth doing are the identification check (if it is genital, bleeding, changing, or you are unsure, see a doctor) and choosing a treatment that fits the subtype.

If you are confident your growth is an ordinary wart and you want it gone, the OcuraLife Plasma Pen was built for precise at-home treatment of this exact category of growth.