Warts: Common Causes, Warning Signs, and When to Worry

Warts are common, usually harmless skin growths caused by certain strains of human papillomavirus (HPV). They often go away on their own, but persistent, painful, changing, or spreading warts should be assessed by a doctor.

Overview: what warts are and why they happen

Warts are small, rough or smooth growths that develop when certain types of human papillomavirus infect the top layer of the skin. They are very common in children and adults, and in most cases they are harmless. Many warts eventually disappear without treatment as the immune system gradually clears the infection.

Even though they are common, not every skin bump is a wart. Corns, calluses, skin tags, moles, and some skin cancers can sometimes look similar. That is why changes in shape, color, bleeding, or persistent pain should not be ignored.

Warts can spread through direct skin contact or by touching surfaces that carry the virus, especially when the skin is broken or damp. They tend to appear more easily when the skin barrier is weakened, such as after shaving, nail biting, or walking barefoot in shared wet areas.

Types of warts and how they look

Different HPV strains cause different kinds of warts. Common warts often appear on the fingers, hands, knees, or around the nails. They usually feel firm and rough and may contain tiny dark dots, which are small clotted blood vessels rather than dirt.

Plantar warts develop on the soles of the feet. Because body weight presses them inward, they may look flatter than hand warts and can feel tender when walking. A cluster of plantar warts can form what is sometimes called a mosaic wart.

Flat warts are smaller, smoother, and often appear in larger numbers on the face, forehead, hands, or legs. Filiform warts are narrow and finger-like, commonly occurring around the mouth, nose, or eyes. Genital warts are a different type of HPV-related condition that affects the genital or anal area and need separate medical evaluation; readers who need more background may find information about genital warts helpful.

• Common warts: rough, raised bumps on hands and fingers
• Plantar warts: painful lesions on the soles of the feet
• Flat warts: smooth, small, slightly raised spots
• Filiform warts: thread-like growths, often on the face
• Periungual warts: warts around or under the nails

Symptoms and warning signs to notice

The main symptom of a wart is a localized skin growth. It may be rough, smooth, flat, or raised depending on the type. Some warts are skin-colored, while others may appear slightly white, yellow, gray, or light brown.

Many warts do not hurt, but location matters. Plantar warts can cause discomfort when standing or walking, and periungual warts around the nails may crack, catch on objects, or interfere with nail growth. Warts on the face may become irritated by shaving or skin care products.

Features that deserve closer attention include bleeding without obvious injury, rapid enlargement, marked color change, an irregular border, repeated infection, or a sore that does not heal. A growth that looks like a wart but does not respond to standard treatment may need reassessment, especially in older adults or in people with a history of skin cancer. In some cases, a doctor may evaluate whether another skin condition, including skin cancer, could be involved.

Causes, spread, and risk factors

Warts are caused by infection with certain non-cancerous skin strains of HPV. The virus enters through tiny breaks in the skin. After exposure, a wart may take weeks or even months to appear, which can make it hard to know where the infection came from.

Warts spread more easily in warm, moist environments such as locker rooms, pool decks, and communal showers. Sharing razors, nail tools, socks, shoes, or towels may also increase the chance of transmission. Picking at a wart can spread the virus to nearby skin.

Some people are more likely to develop warts than others. Risk tends to be higher in children, teenagers, people with eczema or frequently damaged skin, those who bite their nails, and anyone with a weakened immune system. Immunosuppression does not mean a wart is dangerous, but it can make warts more numerous, more persistent, and harder to treat.

How doctors diagnose warts

Doctors usually diagnose warts by examining the skin. The appearance, texture, location, and pattern often provide enough information. A dermatologist may gently pare down a thick wart to look for the tiny pinpoint vessels that support the diagnosis.

Testing is not usually needed for straightforward cases. However, if the lesion is unusual, very dark, ulcerated, resistant to treatment, or located in a sensitive area, a doctor may recommend a closer examination. Sometimes dermoscopy, a magnified skin assessment, helps distinguish a wart from a mole, callus, or another lesion.

In uncertain cases, a small biopsy may be performed to confirm the diagnosis. This is especially important when a growth could represent another skin disorder. If specialist assessment is needed, dermatology evaluation can help clarify the cause and guide treatment options.

Treatment options: from watchful waiting to procedures

Many warts can be managed with watchful waiting, especially if they are not painful or bothersome. Because the immune system often clears them over time, not every wart needs immediate treatment. Still, some people prefer treatment because of discomfort, cosmetic concerns, spread to other areas, or repeated recurrence.

Common first-line treatments include salicylic acid preparations used regularly over time and cryotherapy, which freezes the wart. These approaches work by gradually removing infected skin or triggering an immune response. Depending on the wart type and location, a doctor may also consider prescription topical medicines, cantharidin-based treatment, electrocautery, curettage, laser therapy, or other procedural options.

Home treatment should be used carefully. Cutting, burning, or aggressively scraping a wart at home can cause infection, bleeding, scarring, and spread of the virus. Persistent plantar warts or multiple resistant lesions may benefit from specialist care, including cryotherapy or other office-based wart treatments. If a wart affects walking, work, sports, or nail growth, more tailored care is often helpful.

Prevention and self-care

It is not always possible to prevent warts, but simple habits can reduce the risk of developing them or passing them to others. Keeping skin healthy and intact is one of the best defenses. Moisturizing dry, cracked skin and avoiding repeated picking can lower the chance of viral entry.

Helpful self-care measures include not sharing razors, nail clippers, socks, shoes, or towels, and wearing sandals in public showers or pool areas. Warts should be covered if they are in places where rubbing or contact is common. Hands should be washed after touching a wart, and scratching should be avoided.

People with diabetes, poor circulation, or reduced feeling in the feet should be cautious with any foot lesion and avoid self-treating plantar warts without professional advice. Ongoing skin support and expert care may be appropriate through skin care specialists when diagnosis is uncertain or self-care is not working.

When to seek medical care

Medical care is recommended if a wart is painful, bleeds, grows quickly, changes color, appears infected, or keeps returning after treatment. A doctor should also assess any growth in the genital area, on the face near the eyes, or under the nails if it interferes with normal function.

Prompt evaluation is especially important for people with diabetes, poor circulation, eczema affecting the area, or a weakened immune system. The same is true when there is any doubt about whether the lesion is truly a wart. A skin growth that seems unusual may need a more careful review.

For international patients who need assessment and treatment, Acibadem International offers multidisciplinary care through JCI-accredited hospitals, with specialists experienced in skin conditions and procedure-based wart management.

Frequently asked questions

Do warts go away on their own?

Yes, many warts eventually go away without treatment as the immune system clears the virus. This can take months or sometimes longer, so some people choose treatment if the wart is painful, spreading, or bothersome.

Are warts contagious?

Warts can spread through direct contact with the wart or through contaminated surfaces and objects. The risk is higher when the skin is broken, wet, or irritated, which is why shared shower areas and nail tools can play a role.

What is the difference between a corn and a wart?

Corns are caused by pressure and friction, while warts are caused by a viral skin infection. Warts may interrupt normal skin lines and can show tiny dark dots, whereas corns are usually centered over pressure points and tend to preserve skin lines.

Can a wart turn into cancer?

Common skin warts are usually benign and do not become cancer. However, some skin cancers and precancerous lesions can look like warts, so a changing, bleeding, or treatment-resistant growth should be checked by a doctor.

Should a person remove a wart at home?

Over-the-counter wart treatments may help some common warts, especially on the hands or feet, when used as directed. Home cutting, burning, or picking is not advised because it can cause infection, scarring, and spread to nearby skin.

Why do plantar warts hurt more than other warts?

Plantar warts are pressed inward by body weight when standing and walking. This pressure can make them feel tender, as if there is a pebble in the shoe, even when the wart itself looks relatively small.

References

• American Academy of Dermatology
• Centers for Disease Control and Prevention
• National Health Service
• Mayo Clinic
• Merck Manual Consumer Version

This article is for general information only and is not a substitute for professional medical advice. Please consult a qualified doctor about your individual situation.