Burns are a type of traumatic injury caused by thermal (heat such as fire, steam, tar, or hot liquids), electrical, radiation (UV rays or radiation treatments), chemical, or electromagnetic energy.
Burns are classified as first-degree (mild), second-degree (moderate), or third-degree (severe), depending on how deep and severe they penetrate the skin's surface.
An open flame is the leading cause of burn injury for adults, while scalding is the leading cause of burn injury for children.
Burns can cause swelling, blistering, scarring, and, in serious cases, shock and even death. Burns also can lead to infections because they damage the skin's protective barrier. After a third-degree burn, individuals need skin or synthetic grafts to cover exposed tissue and encourage new skin to grow. First- and second-degree burns usually heal without grafts.
When tissues are burned, fluid from outside the cells leaks into the tissues from the blood vessels, causing swelling and pain. In addition, damaged skin and other body surfaces are easily infected because they can no longer act as a barrier against invading organisms.
More than two million people in the United States require treatment for burns each year, and between 3,000-4,000 individuals die of severe burns. Older people and young children are particularly vulnerable.
About 20% of burns occur in children younger than age five, and most of these are scald burns from hot liquids.
About 60% of burns occur in the 18-64 year-old age group.
About 10% of burns occur in older adults, mostly scald burns from hot liquids.
Men are twice as likely to have burn injuries as women.
The skin is the body's largest organ, covering the body. In addition to serving as a protective shield against heat, light, injury, and infection, the skin also regulates body temperature. The skin also stores water and fat, is a sensory organ, prevents water loss, and prevents the entry of bacteria.
The skin has many important functions. It is composed of several layers, with each layer performing specific functions. The epidermis is the thin outer layer of the skin. The epidermis also contains melanocytes, which are cells that produce melanin (skin pigment). The dermis is the middle layer of the skin. The dermis contains blood vessels, lymph vessels, hair follicles, sweat glands, collagen bundles, fibroblasts, and nerves. The dermis is held together by a protein called collagen, made by fibroblasts. The dermis layer also contains pain and touch receptors. The subcutaneous layer, or subcutis (subQ), is the deepest layer of skin. The subcutis consists of a network of collagen and fat cells. This network helps conserve the body's heat and protects the body from injury by acting as a "shock absorber."

Related Terms

Autograft, cardiopulmonary resuscitation, chemical burn, collagen, CPR, debride, dermis, electrical burn, electromagnetic burn, epidermis, escharotomy, eschars, first-degree burn, friction burns, full thickness burn, hyperalimentation, melanocytes, myoglobin, nasogastric tube, pain receptor, partial thickness burn, perineum, photoaging, radiation burn, radiation treatments, rhabdomyolysis, second-degree burn, skin graft, subcutaneous, subcutis, subQ, sunburn, thermal burn, third-degree burn, touch receptor, ultraviolet rays, UV rays, UVA rays, UVB rays, xenograft.


Burns are classified as first-degree (mild), second-degree (moderate), or third-degree (severe), depending on how deep and severe they penetrate the skin's surface.
First-degree (superficial) burns: First-degree burns, also known as superficial burns, affect only the epidermis, or outer layer of skin. The burn site is red, painful, dry, and with no blisters. Mild sunburn is an example. Long-term tissue damage is rare and usually consists of an increase or decrease in the skin color.
Second-degree (partial thickness) burns: Second-degree burns, also known as partial thickness burns, involve the epidermis and part of the dermis layer of skin. The burn site appears red, blistered, and may be swollen and painful. If a second-degree burn is no larger than two to three inches in diameter, it is treated as a minor burn. If the burned area is larger or if the burn is on the hands, feet, face, groin, or buttocks, or over a major joint, medical attention needs to be received immediately.
Third-degree (full thickness) burns: Third-degree burns, also known as full thickness burns, destroy the epidermis and dermis. Third-degree burns may also damage the underlying bones, muscles, and tendons. When bones, muscles, or tendons are also burned, this may be referred to as a fourth-degree burn. The burn site appears white or charred. There is no sensation in the area since the nerve endings are destroyed.
Note: Babies and young children may have a more severe reaction from a burn than an adult. A burn in an adult may cause a minor loss of fluids from the body, but in a baby or young child, the same size and depth of a burn may cause a severe fluid loss.