The Facts

Burns are injuries primarily to the skin and underlying tissue. The skin is the largest organ in the body and it regulates the body's temperature. It also prevents the evaporation of bodily fluids and acts as a barrier against infection.

Skin damage resulting from burns can be minor or can present a life-threatening emergency, depending on the heat's intensity, the total area of tissues burned, and the length of exposure to the skin.


Burns tend to be caused by a variety of environmental factors:

  • The majority of burns are called flame burns since they're caused by fire. Contact with flame can cause direct injury to the skin and tissue.
  • A wound to the skin caused by a hot liquid is called a scald. The thicker the liquid and the longer its contact with the skin, the greater the scald.
  • Damage to the skin caused by a hot object is called a contact burn. In such instances, the burn is usually confined to the part of skin that touched the hot object. Examples are burns from cigarettes, irons, or cooking appliances.
  • Sunburn involves damage to the skin caused by ultraviolet (UV) rays, which are emitted from the sun.
  • Electrical burns are caused by currents of electricity. These burns are usually very deep and may cause severe damage to the skin and its underlying tissue.
  • Contact with flammable gases or liquids may cause chemical burns. Inhaling hot gases could damage the upper airways, making it difficult to breathe.

Symptoms and Complications

Burns are generally classified according to the depth and extent of injury: first-degree, second-degree, or third-degree burns. There are three layers of skin. Burn depth is dependent on which layer of skin has been damaged. Symptoms range depending on the depth of damage.

First-degree burns involve the outermost layer of the skin, called the epidermis. Redness, tenderness or pain, and swelling usually describe these burns. There's usually no blistering. Complete recovery usually occurs within a week, often with peeling and sometimes with temporary, mild changes in skin tone. First-degree burns often occur after over-exposure to UV rays of the sun, or after coming in contact with a hot object.

Second-degree burns involve damage to the second layer of skin, called the dermis. These very painful burns look pink, moist and soft. Blisters usually appear and fluid might ooze from the skin. Depending on the damage to the dermis, these burns may take anywhere from 2 to 6 weeks to heal. Scarring may result. Such burns often result from severe UV exposure and scalds.

Third-degree burns involve damage to the epidermis, the dermis, and the hypodermis, the third layer of skin. As a result, the full thickness of the skin is damaged. Fat, nerves, muscles, and bones may be affected. Damage of this sort causes the skin to appear a filmy white. The area isn't generally painful because nerve endings have been damaged. Since a large amount of tissue may be destroyed, healing is very slow and considerable scarring results. Later on, contractures (permanent tightening of tissue that prevents normal movement) can occur due to the deep scarring and occasionally tissue may have to be cut or "released" to relieve underlying pressure. Deep burns may result from contact with fires, electricity, or corrosive chemicals.

Inhalational burns can lead to airway swelling and inability to breathe; people with these injuries must be brought to a hospital as soon as possible, even if they initially do not have breathing difficulties.

Making the Diagnosis

A diagnosis is usually formed based on burn depth. However, the severity might also be influenced by the extent of damage to the body.

The extent of a burn is usually based on the "rule of nines" - each arm is considered 9% of the body surface area, each leg is 18%, the back and front of the torso are each considered to be 18%, the head and neck are 9%, and the genital region is 1% of the surface area. Using these classifications, a physician can make a clear diagnosis.

Treatment and Prevention

Treatment decisions are based on the need to relieve pain, reduce swelling, prevent infection, and promote healing.

Many experts believe that a physician should be consulted for any burn except first-degree burns affecting less than 1% of the body's surface. Any second-degree burns covering more than 10% to 15% of the body surface or suspected third-degree burns should be assessed by a physician.

Also, if the eyes, ears, face, or feet are involved, it is important to seek medical attention. However, if these parts haven't been affected, or if there's no blistering, medical attention may not be necessary.

For first-degree (minor) burns, cool moist compresses should be applied immediately. The cool compresses may reduce the swelling and pain. Don't exert pressure on the burned skin. Although no dressing is required, a light dressing may aid the discomfort. A water-based skin moisturizer may be applied if no blisters form, to help the skin heal.

For second-degree burns, the skin should be placed in cool water. If the skin is broken, it should be gently washed by rinsing well with a saline solution. Everyone who develops blisters on their burns should see a doctor. There are differing ideas on how to treat blisters. Some physicians believe that blisters are a protective barrier for the burn. Others feel that the trapped fluid in the blister can become infected. It's important to see a physician so that blister care can be provided. Acetylsalicylic acid* (ASA) or acetaminophen can be taken to help relieve any pain or swelling.

In the case of severe, third-degree burns, emergency medical services should be called immediately. The goal is to prevent infection (one of the most significant problems in burn victims), remove dead tissue, and cover the wound with skin as soon as possible. Cold water should not be applied and clothing that's stuck to the burn shouldn't be removed. Cover the burn loosely with a clean, dry dressing such as a handkerchief, pillowcase, or a sheet. It's important to keep warm after the burn.

People with electrical burns should always see a doctor. Although they may appear superficial, there may be damage to deeper tissues that is not immediately evident. Also, these people may be at risk for cardiac arrhythmias for 72 hours after being burned electrically.

Be cautious of circumferential burns (that is, burns that encircle a limb and may cause circulation problems with scarring), as these should be assessed by your physician.

In all cases, do not - as folklore suggests - apply butter or margarine. These won't relieve pain and may increase the burning sensation. If blisters form and break, it may also lead to infection.


*All medications have both common (generic) and brand names. The brand name is what a specific manufacturer calls the product (e.g., Tylenol®). The common name is the medical name for the medication (e.g., acetaminophen). A medication may have many brand names, but only one common name. This article lists medications by their common names. For information on a given medication, check our Drug Information database. For more information on brand names, speak with your doctor or pharmacist.