Common causes of cyanosis

Some of the maincauses of cyanosis are described below, but you shouldn't use this to diagnose yourself always leave that to a doctor.

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". The cause is usually poor circulation resulting from:

• Raynaud'sphenomenon where the blood supply to certain parts of the body, usually the fingers and toes, becomes temporarily reduced when exposed to cold temperatures
• peripheral arterial disease (PAD) where a build-up of fatty deposits in the arteries restricts blood supply to the legs
• 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 generally and/or lips

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:

• 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 where the airways in the lungs become abnormally widened
• a pulmonary embolism a blood clot in the arteries of the lungs
• neonatal respiratory distress syndrome (NRDS) or acute respiratory distress syndrome (ARDS) where the lungs can't provide enough oxygen for the rest of the body
• drowning or nearly drowning

A problem with the airways:

• choking read what to do ifsomeone is choking
• croup a childhood condition, usually caused by a virus,that affects the airways and causes a barking cough
• epiglottitis inflammation and swelling of the flap of tissue at the back of the throat, usually caused by infection
• anaphylaxis a severe allergic reaction that can restrict the airways

A problem with the heart:

• heart failure where the heart fails to pump enough blood around the body
• congenital heart disease a heart defect present at birth that can affect how blood travels around the heart and body
• cardiac arrest where the heart stops beating

Other causes:

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