Cyanosis is best described as

• A. Bluish discoloration of the skin
• B. Red flushing of the skin
• C. Yellowing of the skin
• D. Pale appearance

Answer: (A)

Cyanosis is the bluish discoloration of the skin and mucous membranes caused by an increased amount of deoxygenated hemoglobin in the blood. This usually means that arterial oxygen content is reduced, either because oxygen is not being delivered effectively (central cyanosis) or because blood flow is restricted in the periphery (peripheral cyanosis). It’s most noticeable in readily visible areas such as the lips, tongue, and nail beds. The other color descriptors point to different problems: red flushing comes from vasodilation or fever, yellowing indicates jaundice from bilirubin buildup, and pallor suggests anemia or poor perfusion. So the best description of cyanosis is the bluish discoloration of the skin.