Cyanosis is a condition characterized by bluish discoloration of the skin, nails or mouth, and is usually a symptom of diseases that can interfere with oxygenation and blood circulation, such as congestive heart failure (CHF) or chronic obstructive pulmonary disease (COPD).
According to the cause, cyanosis can be classified into:
- Peripheral, which happens when the speed of the circulation is diminished, not having sufficient circulation of oxygenated blood to the whole body;
- Central, where the blood already arrives in the arteries without oxygen, being the main cause pulmonary diseases;
- Mixed, which occurs when not only the process of oxygenation that occurs in the lungs is impaired but also the heart can not promote sufficient transport of oxygenated blood.
Venous blood, rich in carbon dioxide and low in oxygen, is transported through the veins into the lungs, where they lose carbon dioxide and gain oxygen, which is transported due to hemoglobin, which is one of the components of red blood cells. Oxygenated blood, called arterial blood, is transported through the arteries to the heart and, consequently, to the whole body.
Main causes
Cyanosis can be caused by any condition that interferes with the process of oxygenation and blood transport and can happen both in adult life and in newborns. The main causes of cyanosis are:
- Pulmonary diseases, such as COPD, pulmonary embolism or severe pneumonia, for example;
- Heart disease, with CHF or thrombosis;
- Drug intoxication, such as Sulfa, for example;
- Tetralogy of Fallot or Blue Baby Syndrome, which is a genetic disease characterized by changes in the heart that decrease its efficiency. See what is and how the treatment of Tetralogy of Fallot is done;
- Changes in hemoglobin, which can be identified by the foot test right after birth - Learn more about the foot test.
In addition, cyanosis is common when there is prolonged exposure to cold, very polluted environment or at high altitudes, as they decrease the efficiency of blood circulation.
The diagnosis is made through physical examination, evaluation of the person's clinical history and laboratory tests that evaluate the hemoglobin concentration in the blood and the efficiency of the gas exchange, which is verified through arterial blood gas analysis. Understand what is and how to understand the blood gas analysis.
How is the treatment done?
The treatment of cyanosis is done according to the cause, and may be indicated the use of oxygen masks, practice of physical exercises to improve blood circulation and oxygenation, or wear warmer clothing when cyanosis is caused by cold, for example.
