Warts are skin growths caused by some types of the human papillomavirus (HPV). Warts form when the virus infects the top layer of your skin and causes your skin cells to grow very fast.

Warts can spread when you come in contact with the virus. You can infect yourself again when you touch the warts and then another part of your body. You can infect others when you share towels, razors, or other personal items.

You are most likely to get warts in places where your skin is broken, such as through cuts, hangnails, closely bitten nails, or scrapes.

Some types of the virus thrive in warm, damp places, such as showers, locker room floors, and swimming pool areas. Warts that you get on your feet (plantar warts) are common in swimmers whose feet are not only moist and softened, but are also scratched and broken by rough pool surfaces.

You won't get warts every time you come in contact with the virus. But some people are more likely than others to get warts.

Warts are usually harmless. In most cases, they go away on their own within months or years. But if they spread or cause pain, or if you don't like the way they look, you may want to treat them.

There are several ways to treat warts. For example, you can:

• Use a home treatment to soften and remove the layers of the skin that form the wart. These treatments include salicylic acid (such as Compound W and Occlusal) or tape occlusion (such as duct tape). You don't need a prescription to use these products.
• Freeze the wart with a very cold liquid that can kill the virus. This is called cryotherapy. You can first try an over-the-counter medicine to freeze your wart. Or you can have your doctor freeze it for you.
• Use a prescription medicine to stop the wart's growth, including retinoid (such as Retin-A and Avita). You can use the medicine at home, but you need a prescription. Retinoid is more commonly used to treat acne and aging skin. But it's sometimes used to treat warts.
• Have surgery that uses an intense beam (laser surgery) or an electrical current (electrosurgery) to burn off the wart. Or you can have the wart cut out (curettage).

If these treatments don't work, you can try putting a medicine on the wart to trigger your immune system to kill the wart virus. Or you can try a medicine called bleomycin that is injected into the wart.

If you have diabetes, peripheral arterial disease, a weakened immune system, or a major illness, talk to your doctor before you use any over-the-counter wart removal products. You may not be able to use them.

The decision to treat your warts is up to you. But you might think about the cost and the time needed to treat them. In most cases, over-the-counter products you can use at home work as well as treatments done in your doctor's office. These home treatments cost less, cause little or no pain, and have a low risk of side effects or scarring. But they may take longer to work.

Treatments for warts don't always work. Even after warts shrink or go away, they may come back or spread to other parts of your body. This is because most treatments destroy the wart but don't kill the virus that causes it.

Studies suggest that:

• Salicylic acid is safe and can get rid of warts in up to 75 out of 100 people who use it. This means that as many as 25 out of 100 people still have warts after treatment.¹ By comparison, a placebo (a medicine that has no active ingredients in it) can get rid of warts in 50 out of 100 people.
• There is currently no proof that cryotherapy is any more effective than salicylic acid.²

Other treatments may not work any better than salicylic acid or cryotherapy. You may need to try several different treatments to find one that works for you.

Side effects depend on the type of treatment. But some can cause:

• Skin irritation, burning, and blistering.
• Pain.
• Scarring.
• Infection.
• Nerve damage.

Your doctor might suggest that you treat your warts if:

• You have a wart that is getting worse and is easily irritated.
• You have a plantar wart that hurts to walk on.
• You don't like the way your wart looks.
• You are worried that your wart might spread to other people or other parts of your body.