Glycyanosis is systemic. In addition to the face and limbs, it also affects the trunk, but the skin of the affected area is warm.

Cyanosis is mostly caused by respiratory failure caused by cardiopulmonary disease, ventilation dysfunction, insufficient pulmonary oxygenation, resulting in reduced blood oxygen saturation.

Due to respiratory insufficiency and insufficient pulmonary oxygenation

Commonly seen in bronchial obstruction pneumonia, chronic obstructive pulmonary disease, diffuse interstitial pulmonary fibrosis, etc.

Due to abnormal channel shunting, part of the venous blood level enters the systemic circulation arteries through the oxygenation of the lungs. Cyanosis will occur if the shunting amount exceeds 1/3 of the cardiac output.

Common in tetralogy of Fallot

It occurs at the ends of limbs and sagging areas. The skin of the affected area is cold, but friction or heating can warm the skin and the cyanosis can subside.

Cyanosis is caused by obstruction of peripheral circulation blood flow

Seen in diseases that cause blood stasis in the systemic circulation and slow peripheral blood flow

Such as right heart failure, effusion pericarditis, cardiac tamponade, constrictive pericarditis, etc.

Commonly seen in diseases that cause reduced cardiac output and local blood flow disorders

Examples include severe shock, exposure to cold and thromboangiitis obliterans, Raynaud's disease

Congenital methemoglobinemia and cyanosis since childhood without heart or lung disease, other causes of abnormal hemoglobin

Poisoning by various chemicals or drugs causes the divalent iron in the hemoglobin molecule to be replaced by trivalent iron, causing it to lose its ability to bind oxygen.

It appeared suddenly, and the venous blood drawn was dark brown. Oxygen therapy was given, but the cyanosis could not be improved. Only intravenous injection of methylene blue or a large amount of vitamin C could the cyanosis subside.

Toxic hyperferritinemia caused by eating large amounts of spoiled vegetables containing nitrite can also cause cyanosis, which is called enterogenic cyanosis.