What causes Gilbert's syndrome?
Gilbert's syndrome is a genetic disorder that's hereditary (it runs in families). People with the syndrome have a faulty gene which causes the liver to have problems removing bilirubin from the blood.
Normally, when red blood cells reach the end of their life (after about 120 days), haemoglobin – the red pigment that carries oxygen in the blood – breaks down into bilirubin.
The liver converts bilirubin into a water-soluble form, which passes into bile and is eventually removed from the body in pee or poo. Bilirubin gives pee its light yellow colour and poo its dark brown colour.
In Gilbert's syndrome, the faulty gene means that bilirubin isn't passed into bile (a fluid produced by the liver to help with digestion) at the normal rate. Instead, it builds up in the bloodstream, giving the skin and white of the eyes a yellowish tinge.
Other than inheriting the faulty gene, there are no known risk factors for developing Gilbert's syndrome. It isn't related to lifestyle habits, environmental factors or serious underlying liver problems, such as cirrhosis or hepatitis C.