What can cause redness of the skin?

Redness of the skin, also known as erythema, is primarily caused by excess circulation to a particular area of the body. This increased blood flow can occur due to various reasons, such as inflammation, infection, or localized injury, where the body directs more blood to the affected area as part of its healing response. The blood vessels dilate to allow more blood to reach the area, resulting in a noticeable reddening of the skin.

Other factors, while contributing to skin changes, do not directly lead to the same effect. Liver disease can cause changes to the skin's color and texture over time, but it doesn’t directly induce localized redness. Similarly, low blood pressure tends to result in paleness rather than redness, as there is reduced blood flow overall. Extreme cold exposure causes a different physiological response, leading to constriction of blood vessels and often resulting in paleness or a bluish discoloration rather than redness. Thus, increased circulation is the most direct and immediate cause of skin redness.