Blue skin and lips (cyanosis)

When to seek emergency help

Call 999 or go to your nearest emergency department immediately if you notice an adult or child suddenly turning blue.

This is particularly important if they have other symptoms, such as:

• difficulty breathing
• chest pain

This could be a sign of a life-threatening problem.

When to see your GP

See your GP if you have cyanosis that:

• comes on very gradually
• 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.

Common causes of cyanosis

When blood has less oxygen than normal, it changes from bright red to a darker colour, making the skin and lips look blue. 

Some of the main causes of cyanosis are described below. You shouldn't use this to diagnose yourself. You should always leave that to your GP.

Cyanosis that just affects the hands, feet or limbs

If just the fingers, toes or limbs have turned blue and feel cold, it's known as peripheral cyanosis.

It can be caused by being exposed to cold air or water. Other causes include poor circulation resulting from:

• Raynaud's phenomenon
• peripheral arterial disease (PAD) 
• beta-blockers – medication commonly used to treat high blood pressure
• a blood clot blocking the blood supply to or from a limb

Cyanosis that affects the skin and/ or lips

When all the skin and/ or lips have a blue tinge, it's known as central cyanosis.

It 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:

• worsening of a long-term lung condition, such as asthma or chronic obstructive pulmonary disease (COPD)
• lung infections, such as pneumonia, bronchiolitis or whooping cough
• bronchiectasis
• a pulmonary embolism 
• neonatal respiratory distress syndrome (NRDS) or acute respiratory distress syndrome (ARDS)
• drowning or nearly drowning

A problem with the airways:

• choking
• croup
• epiglottitis
• anaphylaxis (severe allergic reaction)

A problem with the heart:

• heart failure
• congenital heart disease
• cardiac arrest

Other causes:

• exposure to cold air or water
• being at high altitude
• fits (seizures) that last a long time
• a problem with the blood, such as abnormal haemoglobin (the blood can't take up enough oxygen) or a high concentration of red blood cells (polycythaemia)

More useful links

• How to use your health services