Definition of Skin discoloration - bluish:

Cyanosis is a bluish color to the skin or mucus membranes that is usually due to a lack of oxygen in the blood.

Considerations:

Red blood cells provide oxygen to body tissues. Most of the time, almost all blood cells carry a full supply of oxygen. These blood cells are bright red, and the skin has a pinkish or red hue.

Blood that has lost its oxygen is dark bluish-red. People whose blood is low in oxygen tend to have a bluish color to their skin, called cyanosis.

Depending on the cause, cyanosis may develop suddenly, along with shortness of breath and other symptoms.

Cyanosis that is caused by long-term heart or lung problems may develop slowly. Symptoms may be present, but are often not severe.

When oxygen levels have dropped only a small amount, cyanosis may be hard to detect.

In dark-skinned people, cyanosis may be easier to see in the mucus membranes (lips, gums, around the eyes) and nails.

Common Causes:

Cyanosis that is seen in only one part of the body may be due to:

• A blood clot that blocks the blood supply to a leg, foot, hand, or arm
• Raynaud's phenomenon

LACK OF OXYGEN IN THE BLOOD

Most cyanosis occurs because of a lack of oxygen in the blood. This can be caused by the following problems.

Problems with the lungs:

• Blood clot in the arteries of the lungs (pulmonary embolism)
• Infection in the smallest air passages in the lungs of children, called bronchiolitis
• Long-term lung problems that become more severe, such as COPD, asthma, and interstitial lung disease
• Drowning or near-drowning
• High altitudes
• Pneumonia (severe)

Problems with the airways leading to the lungs:

• Breath-holding
• Choking on something stuck in the airways
• Croup
• Epiglottitis
• Seizures that last a long time

Problems with the heart:

• Heart failure
• Heart defects that are present at birth (congenital)
• Heart stops working (cardiac arrest)

Other problems:

• Drug overdoses (narcotics, benzodiazepines, sedatives)
• Exposure to cold air or water
• Toxins such as cyanide