Cyanosis is a blue or purple discolouration 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 signs and symptoms of the condition?
When someone has cyanosis, the doctor will need more information. Questions may be asked about:
Though mild cyanosis may be hard to detect, especially in dark-skinned people, severe cases are usually obvious.
- what areas of the body are affected
- when the cyanosis started and how often it occurs
- whether the cyanosis is related to cold weather, stress, or smoking
- if the person has any trouble breathing, or shortness of breath
- whether there is any numbness or tingling in the arms or legs
- whether the person has any chest pain
- other symptoms, such as coughing, weakness, headache, wheezing, fever, chills, weight loss, fast heartbeat, fatigue, pain, or ulcers on the legs
- whether the person has any history of heart or lung diseases
- what medications the person takes
What are the causes and risks of the condition?
Cyanosis may be caused by a number of conditions, including:
What can be done to prevent the condition?
- narrowing of the arteries or veins in the affected area, such as narrowed arteries from arteriosclerosis
- 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
- lung cancer
- 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
Prevention depends on the cause. Avoiding cold weather or wearing warm clothes can prevent cases due to cold exposure. A person who avoids smoking can decrease the risk of COPD, pneumonia, lung cancer, artery blockage, and heart disease. Many cases cannot be prevented.
How is the condition diagnosed?
The doctor can identify cyanosis by examining the person. The cause must then be found. A history and full examination will be needed first.
To help figure out the cause, other tests are often ordered. A blood test called a full blood count, or FBC, can make sure there are a normal number of blood cells. A blood test called an arterial blood gas can measure the level of oxygen in the blood. This can also be done with a device that attaches to the finger called a pulse oximeter. A chest x-ray can show many heart and lung disorders. A test that uses sound waves to look at the heart, called an echocardiogram, may be used. This test can show many of the congenital heart defects that may cause cyanosis and measure how well the heart is pumping blood. Other tests may be needed in some cases.
What are the long-term effects of the condition?
Long-term effects depend on the cause of the cyanosis. If pneumonia is the cause, antibiotics may cure the infection, and there may be no long-term effects. If the cyanosis is related to an airway blockage, it may improve once the blockage is removed. If the cause is lung cancer, permanent breathing problems or death may result.
What are the risks to others?
Cyanosis itself is not contagious. But if an infection, such as pneumonia, caused the cyanosis, this infection may be contagious.
What are the treatments for the condition?
Treatment depends on the cause. Infections are often treated with antibiotics. Avoiding exposure to cold temperatures or warming the body may eliminate cyanosis related to cold temperatures. Oxygen may be needed to relieve shortness of breath. Some conditions, such as heart defects present at birth, may be treated with open heart surgery. Diuretics, or water pills, and other heart medications may be needed if heart failure is the cause. Surgery, chemotherapy, or radiation therapy may be needed for lung cancer.
What are the side effects of the treatments?
Side effects depend on the treatments used. All medications have possible side effects. For example, antibiotics can cause stomach upset, allergic reaction, and other effects. Surgery poses a risk of infection, bleeding, or reaction to any analgesia used. Chemotherapy can cause many side effects, such as stomach upset, hair loss, and weakness.
What happens after treatment for the condition?
In many cases, no further measures are needed after treatment, and the person may be able to return to normal activities. In other cases, the cause is not curable and needs further treatment. In some cases, death may occur, such as from lung cancer.
How is the condition monitored?
Monitoring also depends on the cause. The level of oxygen in the blood can be measured repeatedly with arterial blood gases until the person improves. Chest pain, difficulty breathing, a feeling of tightness in the throat, confusion, or severe weakness are worrisome. A person should seek immediate medical attention for these symptoms.
Reviewer: eknowhow Medical Review Panel
Editor: Dr John Hearne
Last Updated: 18/09/2004
Potential conflict of interest information for reviewers available on request