Bilirubin in urine
Bilirubin is normally excreted in humans through the bile and further through the intestines. However, a smaller proportion is also eliminated from the body through the kidneys and thus through urine. The kidneys can only excrete the conjugated or direct bilirubin.
Indirect bilirubin is bound in the blood to the protein albumin, which due to its size cannot be filtered through the kidneys and therefore remains in the blood. Direct bilirubin, on the other hand, is freely available in the blood and is correspondingly small enough to pass through the kidney filter. Nevertheless, the amount of bilirubin excreted via the kidneys is very small and almost undetectable in healthy people.
However, if normal bilirubin excretion via the bile and intestines is not possible, the bilirubin concentration in the blood rises sharply. As a result, more bilirubin is filtered in the kidney and finally excreted with the urine. If this happens in larger quantities, the urine appears brownish in colour.
The suspicion of increased bilirubin levels can be substantiated by the so-called “shaking foam test”. If the urine sample is shaken and the resulting foam is brown-yellow in colour, this indicates an increased bilirubin concentration. If the foam is whitish, however, this is less likely.
How can you lower bilirubin?
Elevated bilirubin levels in adults are almost always a sign of disease or damage. Therefore, the best way to reduce bilirubin levels is always to treat these causes medically. In the case of jaundice due to elevated bilirubin values, a visit to the doctor should always be made.
Since bilirubin levels are elevated especially in poor liver health, improvements in diet and lifestyle can also have a positive effect on liver and especially bilirubin levels. This includes ensuring a balanced diet and maintaining a healthy body weight. Severe overweight, excessive alcohol consumption and frequent consumption of high-fat and sweetened foods should be avoided.
Certain drugs can also impair or even damage the liver in its work. These include over-the-counter medicines such as paracetamol. For this reason, the use of such drugs should always be discussed with your doctor if your liver values are elevated.
Many alternative preparations or cures that promise to strengthen or cleanse the liver have not been scientifically proven to be effective and are therefore highly controversial. In addition, some of the ingredients used seem to have a more liver-damaging effect, such as concentrates of green tea. Caution is therefore advised here.
How is the bilirubin increased?
An increase in bilirubin levels can have many causes due to the complexity of the bilirubin metabolism. Therefore, the cause should always be clarified by a doctor. Here, the distinction between pre-, intra- and posthepatic jaundice described above is of great importance.
A prehepatic icterus is present when the cause of the bilirubin increase is to be found “before” the liver. In most cases, the cause here is increased haemolysis, i.e. the destruction of red blood cells. As a result, more bilirubin is produced than can be metabolized in the liver and the concentration increases.
The cause can be genetic diseases of the red blood cells. Various infectious diseases also cause prehepatic jaundice. The causes of intrahepatic icterus, on the other hand, are located in the liver.
These include cirrhosis of the liver or an inflammation of the liver tissue, the so-called hepatitis, which can have various causes. These include poisoning, autoimmune diseases, but also infectious diseases. There is also a larger group of genetic causes.
Some, like the widespread Gilbert’s disease, are considered harmless. Others, such as Crigler-Najjar syndrome, which occurs in newborns, are potentially more dangerous, but are easily treatable. A liver tumour can also increase bilirubin levels.
Reasons for posthepatic jaundice are diseases of the bile ducts. A frequent cause is choledocholithiasis, i.e. the obstruction of the main bile duct by a gallstone. There are also a number of inflammatory diseases of the bile ducts and surrounding organs which can cause posthepatic jaundice. Various tumour diseases can also affect the bile ducts.
