The term refers cyanosis bluish color that take the skin and mucous membranes when blood contains more than 5% of deoxygenated hemoglobin. In fact, it is more accurate to say that cyanosis appears when more than 5g/dl blood hemoglobin is deoxygenated form (not bound to the oxygen). So it is a sign of hypoxia and not hypoxia (blood levels of dissolved oxygen). It is among others a sign of renal hypoxic respiratory serious.

It can be caused by a disorder of movement, an alteration of the oxyhemoglobin or disorder of the blood gas. It may be the consequence, inter alia, pulmonary disorders, congenital heart defects, poor blood circulation, an anemia or poisoning.

There are 2 main types of cyanosis:

The central cyanosis

It is associated with a desaturation of arterial oxygen. The disease reached the entire body. It may have originated in 2 cases:

A problem of pulmonary blood gas (eg bronchopneumonia). The portion of oxygen in the blood is decreased.
A circulatory problem. There septal. (congenital heart defect with a right-left shunt (eg tetralogy of Fallot)

(shunt most common is the left-right shunt, due to the higher pressure in the systemic circulation. The right-left shunt is normally in the fetus and in newborn young, before the closure of the ductus arteriosus occurring in the first days after birth, there is a slight left-right shunt)

The peripheral cyanosis

It is linked to venous desaturation caused by extraction of oxygen from the blood more substantial fabrics. Circulatory failure resulting stagnation of blood and elevation extraction. It happens when the concentration of reduced hemoglobin exceeds 5 g/100 ml of blood capillaries. This condition can reach the whole body or be localized as in the superior vena cava where it reached only the parties drained by the vena cava.


Acrocyanosis refers to a persistent blue or cyanotic discoloration of the digits, most commonly occurring in the hands although also occurring in the face and feet as well.

The acrocyanosis is different from Raynaud's disease is paroxysmal (occurs anytime). Android app