Changes in Skin Color: Clinical Perspectives

Changes in human skin color can help diagnose pathological conditions or emotional responses by the body.

For instance, in cyanosis or blueness, the skin appears blue due to low oxygen levels. Particularly seen in the skin, mucous membranes and nail beds, it can be a sign of cardiovascular or respiratory disorders.

A yellowish appearance of skin and sclerae of the eyes—typically observed in jaundice—is caused by the accumulation of a yellow pigment called bilirubin in tissues.  This skin condition occurs either due to the excessive breakdown of red blood cells or liver dysfunction.

Ecchymoses, commonly called bruises, are generally seen as black-and-blue marks on the skin. They can happen when blood leaks from damaged blood vessels and clots under the skin, but the epidermis remains unbroken.

Erythema, or redness, can occur because of increased blood flow due to localized capillary dilation. It generally indicates a skin injury, infection or inflammation.