How Do Burns Happen?

What do fire, chemicals, and electricity have in common? They can all cause burns! Simply put, a burn is an injury to the skin—or even to the layers beneath it—caused by heat or other harmful sources. Burns are not just caused by fire. Too much sun exposure, hot liquids, electricity, and even chemicals can also cause burns. In fact, for children under 5 years old, burns most commonly happen in the kitchen or dining room when kids pull hot liquids onto themselves from stoves and microwaves [1]. Burns in children are also often caused by electric fireplaces and hot bath water, so it is important to check the temperature of these to prevent injuries.

Burns by Degree

Just how bad can a burn get? Well, it depends on how deep it goes. Think of your skin like the layers of a cake. Some burns only affect the outer frosting, while others go all the way to the deepest layers. Burns are usually grouped into four types based on how deep they go, with higher numbers meaning worse and deeper burns. A first-degree burn only affects the outermost layer of the skin. This can happen when you get a sunburn or touch a hot pan. A second-degree burn, also called a partial-thickness burn, affects the layer just under the skin and results in blisters. An easy way to remember this type of burn is with a quick rhyme: “If blisters are what you see, it is likely second degree”. A third-degree burn is also known as a full-thickness burn. This is when all the layers of the skin are affected, reaching the fat and underlying tissues. The final and worst type is a fourth-degree burn. These severe burns do not just harm the skin but can also damage muscles, bones, and even organs [2]! (Figure 1).

Pain and Infections

Are burns painful? Most of the time, yes—but not always. Third and fourth-degree burns can be so deep that they destroy the skin’s pain sensors, which are called nociceptors. These tiny nerves send pain signals to the brain to warn you when something is too hot or dangerous. But when they get damaged by a severe burn, they stop working, which means a person might not feel pain even though the injury is very serious [3]. Because of this, every burn should be seen at a burn center no matter the size.

Burns can affect much more than just pain receptors and nerves. They can also lead to infections. The skin is the body’s first line of defense against microorganisms like bacteria, viruses, and fungi. If the skin gets damaged because of a burn, people are more likely to get an infection.

Without proper care, an infection can spread to other parts of the body which can make recovery more difficult.

How do Burns Heal?

Now that you know what burns are, let us explore how they heal. This process happens in three stages: inflammation, proliferation, and remodeling. In the first stage, the body responds to a severe burn by initiating an inflammatory response, similar to how it fights infections. Right after a burn, blood vessels in the injured area widen, allowing immune cells to rush in and clear damaged tissue while preventing infection. In the second stage, the body starts to rebuild. New skin cells grow quickly, new blood vessels form to bring blood and nutrients to the injured area, and cells make a protein called collagen to fill in the damaged skin. In the last stage, the body cleans up its work. The collagen gets rearranged so the new skin becomes stronger and smoother. This last stage can take months or even years to finish.

Superficial burns typically heal within 2 weeks with minimal scarring, but deeper burns heal more slowly and are at higher risk for hypertrophic scarring (HTS), which can cause thick, raised scars due to excessive collagen production [4].

So, what can be done do to help burns heal? It should not come as a surprise that this depends on the severity of the burn. For minor burns, remove any clothing from the burned area and run cool (not cold) water over it for 20 min within the first 3 h [5]. Do not use ice because this reduces blood flow to the area and can worsen the burn injury. Aloe gel can help soothe the area, and a clean bandage can protect it. For more serious burns—like those involving the face, or covering the whole arm, leg, or chest (leading to swelling), or if a child younger than 5 years old is burned—go to a hospital immediately. Some of these burns may require surgery in the form of skin grafts. In this procedure, doctors take a piece of skin from an unaffected area and transfer it to the burn to heal that area of the skin. It is also important to remove any jewelry around the burn area, but do not pop any blisters. The key to burn healing is keeping the area clean, preventing infection, and getting medical attention when needed. If you are struggling with scars, itching, or pain after a burn, help is available at burn centers.

Summary

Burns are common injuries that can range from mild to life-threatening. While the body has an incredible ability to heal, deeper burns take longer to recover, leave lasting scars, and may require surgery. Understanding how burns happen, how they heal, and how to treat them can properly help prevent complications and promote better recovery. If you are interested in learning more about burns, please visit the American Burn Association for more information.

Glossary

Nociceptors: ↑ Specialized sensory nerves that detect and transmit pain signals to the brain.

Microorganisms: ↑ Microscopic organisms including bacteria, viruses, or fungi.

Inflammation: ↑ The immune system’s response to harmful stimuli, such as microorganisms, damaged cells, or toxic compounds, aimed at removing the threat and starting the healing process.

Proliferation: ↑ The phase in which new skin cells rapidly multiply, blood vessels form, and cells produce collagen to rebuild the damaged tissue.

Remodeling: ↑ The final stage of wound healing where collagen is reorganized, excess scar tissue is reduced, and the newly formed skin strengthens and becomes more functional.

Hypertrophic Scar: ↑ A thick, raised scar that forms due to excessive collagen production during the wound-healing process, often remaining within the original wound boundaries but causing functional concerns.

Collagen: ↑ The main structural protein found in skin and other connective tissues.

Skin Graft: ↑ A surgery where doctors take a piece of healthy skin and attach it to a burned area to help it heal.

Conflict of Interest

The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

AI Tool Statement

The author(s) declared that generative AI was not used in the creation of this manuscript.

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