MICROANATOMY

Detailed explanation-1: -Cyanosis is the medical term for when your skin, lips or nails turn blue due to a lack of oxygen in your blood. If you have darker skin, cyanosis may be easier to see in your lips, gums, nails and around your eyes. The word cyanosis comes from the word cyan.

Detailed explanation-2: -Cyanosis is caused due to an absolute increase in the deoxygenated hemoglobin. Therefore, in anemic patients, greater desaturation of arterial hemoglobin is required for cyanosis to manifest, as compared to individuals with normal hemoglobin levels.

Detailed explanation-3: -Even with normal arterial oxygenation, cyanosis can occur when there is increased extraction of oxygen at the capillary level because the average of arterial and venous oxygen saturation will be lower.