Most burns are minor injuries that occur at home or work. It is common to get a minor burn from hot water, a curling iron, or touching a hot stove. Home treatment is usually all that is needed for healing and to prevent other problems, such as infection.

There are many types of burns.

• Heat burns (thermal burns) are caused by fire, steam, hot objects, or hot liquids. Scald burns with hot liquid are the most common burns to children and older adults.
• Electrical burns are caused by contact with electrical sources or by lightning.
• Chemical burns are caused by contact with household or industrial chemicals in a liquid, solid, or gas form. Natural foods such as chili peppers, which contain a substance irritating to the skin, can cause a burning sensation.
• Radiation burns are caused by the sun, tanning booths, sunlamps, X-rays, or radiation therapy for cancer treatment.
• Friction burns are caused by contact with any hard surface such as roads ("road rash"), carpets, or gym floor surfaces. They are usually both a scrape (abrasion) and a heat burn. Friction burns to the skin are seen in athletes who fall on floors, courts, or tracks. Motorcycle or bicycle riders who have road accidents while not wearing protective clothing might get friction burns. For information on treatment for friction burns, see the topic Scrapes.

Breathing in hot air or gases can injure your lungs (inhalation injuries ). Breathing in toxic gases, such as carbon monoxide, can cause poisoning.

Burns injure the skin layers and can also injure other parts of the body, such as muscles, blood vessels, nerves, lungs, and eyes. Burns are defined as first-, second-, third-, or fourth-degree, depending on how many layers of skin and tissue are burned. The deeper the burn and the larger the burned area, the more serious the burn is.

• First-degree burns are burns of the first layer of skin. See a picture of a first-degree burn.
• There are two types of second-degree burns:
  • Superficial partial-thickness burns injure the first and second layers of skin. See a picture of this type of second-degree burn.
  • Deep partial-thickness burns injure deeper skin layers. See a picture of this type of deep second-degree burn.
• Third-degree burns (full-thickness burns) injure all the skin layers and tissue under the skin. See a picture of a third-degree burn. These burns always require medical treatment.
• Fourth-degree burns extend through the skin to injure muscle, ligaments, tendons, nerves, blood vessels, and bones. These burns always require medical treatment.

The seriousness of a burn is determined by several factors, including:

• The depth, size, cause, affected body area, age, and health of the burn victim.
• Any other injuries that occurred, and the need for follow-up care.