MSD Manual

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Reviewed/Revised May 2023
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Topic Resources

What are burns?

Burns are injuries, usually to your skin, that are caused by heat, sunlight, electricity, radiation, or chemicals.

  • Burns can cause pain, blisters, swelling, and skin loss

  • Burns from heat or chemicals usually affect your skin but sometimes can affect muscles, fat, or bones

  • Small, shallow burns can often be treated at home by keeping the area clean and using an antibiotic burn cream

  • Deep, severe burns can cause other problems, such as shock, severe infections, and death, and often require skin grafts

See a doctor right away if your burn:

  • Is large (for example, bigger than your open hand)

  • Has blisters (small bumps with fluid in them)

  • Darkens the color of your skin, or breaks your skin

  • Is on your face, hand, foot, or genitals (sex parts)

  • Isn’t completely clean

  • Causes pain that isn’t helped by pain medicine, such as acetaminophen

  • Causes pain that is just as bad a day or more later

What causes burns?

How do doctors classify burns?

Doctors classify burns based on:

  • How deeply you were burned

  • How much of your body was burned

Depth of burns

Skin has 3 layers. The layers are thicker on some parts of your body than others. Doctors classify burns based on how deep it is:

  • First-degree burns are the least severe and injure only the top layer of skin

  • Second-degree burns go a little deeper and injure the middle layers of skin

  • Third-degree burns are the most severe and injure all layers of skin

First-degree burns aren't deep enough to cause scars. Third-degree burns and bad second-degree burns typically cause scars.

Getting Under the Skin

The skin has three layers. Beneath the surface of the skin are nerves, nerve endings, glands, hair follicles, and blood vessels. Sweat is produced by glands in the dermis and reaches the surface of the skin through tiny ducts.

Getting Under the Skin

Size of burns

Doctors describe the size of a burn based on how much of your body was burned. If your entire body was burned, that would be a 100% burn. A small burn the size of your hand and fingers is about a 1% burn. Burns that cover an area the size of one of your arms is about a 9% burn.

Severity of burns

The bigger and deeper burns are, the more dangerous they are. Also, burns on some body parts are more dangerous than others. Doctors classify burns as minor, moderate, or severe depending on how much skin got burned and which body parts got burned.

Minor burns are:

  • First-degree burns

  • Second-degree burns that cover less than 10% of your body

Moderate and severe burns are:

  • Any burns on your hands, feet, face, or genitals

  • Second-degree burns that cover more than 10% of your body

  • Third-degree burns that cover more than 1% of your body

What are the symptoms of burns?

Symptoms depend on how deep your burn is:

  • First-degree burns are red, swollen, and very painful.

  • Second-degree burns are also red and very painful, but blisters develop. Blisters may appear right away or sometimes during the first day.

  • Third-degree burns usually don't hurt much because they damage the nerves that feel pain. The burned skin feels leathery and may be white, black, or bright red.

What are the complications of burns?

Your skin keeps germs and dirt out of your body and keeps body fluids and heat in. So, with a severe burn, you may:

Very large burns may be fatal.

Skin heals by growing new skin from its deeper layers. Shallow burns can heal on their own. However, deep burns can damage the growing layer of skin. When this growing layer is damaged:

  • The burn heals with scar tissue instead of new skin

Scar tissue is stiffer than normal skin. If scar tissue is near one of your joints, that joint will be hard to move and can be stuck in a bent position.

How do doctors treat burns?

Doctors first make sure that whatever burned you has stopped. Clothing that has melted or has chemicals on it is taken off. After that, doctors treat burns depending on the type of burn you have.

For first-degree burns (burns that are just red), you should:

If your burn is in an area covered by clothing, put a clean bandage on the burn. You don't need bandages on first-degree burns to your face.

For small second-degree burns (burns that have blisters), see a doctor. The doctor will usually:

  • Clean the burn and take off any broken blisters

  • Put antibiotic burn cream or a special burn dressing on the burn

  • Cover the burn with a clean bandage

  • Have you gently wash the burn and put on fresh antibiotic burn cream and a clean bandage every day— special burn dressings can stay on for several days

  • Remove any unbroken blisters after a few days

  • Have you follow up regularly to look for signs of infection and to see how your burn is healing

Minor second-degree burns typically heal in a week or two.

For severe burns, go to the hospital. The doctors may:

  • Admit you to a hospital that has a special burn unit

  • Give you lots of IV fluids (fluids directly into your vein)

  • Give you pain medicine

  • Do surgery to remove dead burned skin and then cover the area with a skin graft

A skin graft is another term for skin transplant. Skin grafts may be done with:

  • A patch of your own skin from an unburned area

  • Skin from a cadaver (a dead human body)

  • Skin from an animal

  • Artificial skin

Only grafts of your own skin are permanent. Your body eventually rejects cadaver skin, animal skin, or artificial skin. Doctors use those grafts temporarily until they can do a graft with your own skin. If you are burned over a large area, doctors may need to do several skin graft procedures.

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