Cyanosis

Inadequate level of oxygen in the blood

- Dr Mahantesh R. Charantimath

Medically Cyanosis is an unusual bluish, greyish, or purple colour of the skin and mucous membranes, which is normally found around the lips, fingernails, mouth or palms. This is caused due to inadequate level of oxygen in the blood. Oxygen delivery is measured on the basis of cardiac output and arterial oxygen content. Normally about 98% of oxygen is bound to haemoglobin (approx. - 1.34 mL per 1 g of haemoglobin) and only 2% is dissolved in plasma (approx. 0.003 mL of oxygen per 100 mL of plasma).

Blood is red in colour because of presence of oxygen in the blood. This keeps the skin tone in pink or red tinge. If the blood does not have sufficient oxygen it carries waste carbon dioxide from cells and lungs, which is obviously dark in colour. This makes bluish ting on skin so it must be addressed immediately.

It is seen in new-borns with lung and breathing problems, heart defects (if it allows blood that is not fully oxygenated to pass through arterial circulation) and respiratory distress syndrome. It can also appear at any time later in life when there is insufficient oxygen supply to the blood.