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If a person's skin or lips turn blue, it's usually caused by low blood oxygen levels or poor circulation. It can be a sign of a serious problem, so it's important to seek medical advice.
When blood becomes depleted of oxygen, it changes from bright red to darker in colour, and it's this that makes the skin and lips look blue.
In darker-skinned people, the blue tinge may be easier to spot in the lips, gums and around the eyes.
The medical name for this blue tinge is cyanosis.
Call 999 or go to your nearest hospital emergency department (A&E) immediately if you notice an adult or child suddenly turning blue, particularly if they have other symptoms, such as difficulty breathing or chest pain. This could be a sign of a life-threatening problem.
See your GP or call NHS 111 if you have cyanosis that comes on very gradually, or affects just the fingers, hands, toes or feet. This is usually the result of a less serious problem with blood circulation, but it should still be checked by a doctor.
Some of the main causes of cyanosis are described below, but you shouldn't use this to diagnose yourself – always leave that to a doctor.
If just the fingers, toes or limbs have turned blue and feel cold, it's known as peripheral cyanosis.
The cause is usually poor circulation resulting from:
When all the skin and/or lips have a blue tinge, it's known as central cyanosis, and is usually a sign of low levels of oxygen in the blood. Common causes for central cyanosis are listed below.
A problem with the lungs:
A problem with the airways:
A problem with the heart: