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Why does skin redden around an injury or infection?

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Learn how regenerative properties of the skin helps to protect the human body from the external environment — human skin Human skin, whose cells are generated continuously by the body, serves as a protective barrier between the inside of the human body and the environment.

When skin is injured or infected, it undergoes an acute inflammatory response, which is the body’s natural process to initiate healing and protect against further damage.12

The redness, medically known as erythema, is primarily caused by the dilation of blood vessels in the affected area, a process called vasodilation. This dilation increases blood flow to the site of the injury, which is essential for delivering white blood cells and other immune components necessary to clear cellular debris and fight potential infection.1234

This response is triggered by the release of chemical mediators—such as histamine, peptides, and fatty acids—in the skin. In addition to causing redness, these vascular changes increase the permeability of blood vessel walls, allowing fluid and proteins to enter the surrounding tissue, which results in swelling. While this process can be painful or uncomfortable, it is a vital biological mechanism for tissue repair and defense.2514