Cyanosis is a blue or purple discoloration of the skin that can occur when there is not enough oxygen in a person's blood or tissues.
What is going on in the body?
Cyanosis is usually caused by either serious lung or heart disease, or circulation problems. Cases due to circulation problems are more common and often less serious. They usually affect the ends of the arms or legs or both. When cyanosis is due to heart or lung disease, it often affects the face and the arms and legs.
What are the causes and risks of the condition?
Cyanosis may be caused by a number of conditions, including:
narrowing of the arteries or veins in the affected area, such as narrowed arteries from atherosclerosis
exposure to cold temperature
Berger's disease, which is thought to be caused by smoking and results in cyanosis of the hands and feet.
chronic obstructive pulmonary diseases (COPD), such as emphysema, which are usually caused by smoking
congestive heart failure, a condition in which the heart is unable to pump enough blood throughout the body
deep vein thrombosis, or a blood clot, which usually occurs in the leg and causes only the affected leg to have cyanosis
severe asthma, choking, or blockage in the windpipe
pneumonia, which is an infection in the lungs
cystic fibrosis, an inherited condition that affects the lungs and other organs
pulmonary embolism, which is a blood clot in the lungs
Raynaud's disease, a condition that occurs for unknown reasons and can cause cyanosis and pain in the fingers
shock, which is very poor circulation throughout the body
congenital heart disease, or heart defects present at birth
other serious lung and heart diseases