What is jaundice in adults?
In adults, jaundice can not be considered a disease, but a sign that can be caused by various diseases.
Jaundice is the yellowing of the skin and sclera (sclera) of the eyes and is caused by increased bilirubin in the blood (hyperbilirubinemia).
The color of the skin and sclera varies depending on the level of bilirubin:
- yellowish, if the bilirubin is only slightly elevated,
- brownish, if the bilirubin is significantly increased.
Jaundice is when bilirubin levels exceed 2.5 mg/dl or when total bilirubin is higher than 13 mg/dl in newborns or 15 mg/dl in premature infants.
Subjaundice is a term used when bilirubin levels in the blood are between 1.5 and 2.5 mg/dl.
Conjugated and unconjugated bilirubin
Bilirubin is a breakdown product of heme, a component of hemoglobin found in red blood cells.
Before reaching the liver, bilirubin is indirect or “unconjugated”, i.e. it is a water-insoluble form that combines with a protein (albumin) in order to circulate in the blood.
In the liver, bilirubin combines with glucuronic acid to obtain a water-soluble form called direct or conjugated bilirubin.
The conjugated bilirubin passes from the liver to the large intestine, where it is converted into the unconjugated form and excreted from the body.
If the red blood cells die naturally, bilirubin is produced as a by-product of the waste products.
If the function is undisturbed, the stool should be chestnut brown and the urine light yellow in color.
Causes of jaundice in adults
There are three types of jaundice, depending on the cause of bilirubin accumulation in the body.
1. Prehepatic (or hemolytic) jaundice – caused by an overproduction of bilirubin and occurs before the substance is transported through the blood to the liver.
If an infection or disease destroys the red blood cells prematurely, the levels of bilirubin increase. This is called prehepatic jaundice.
Diseases that can provoke this disorder include malaria, sickle cell anemia, thalassemia, Gilbert’s syndrome, hereditary spherocytosis and Crigler-Najjar syndrome.
2. Intrahepatic jaundice (also known as hepatocellular jaundice) – the accumulation occurs within the liver. In the liver, there are two options:
- The liver cells release conjugated bilirubin but are unable to convert unconjugated bilirubin.
- There is a disturbance in the metabolism or in the detection of bilirubin.
If the liver is damaged, it can lead to disturbances in the processing of bilirubin. This leads to intrahepatic jaundice. Liver damage can be a consequence of:
- alcoholic hepatopathy,
- liver tumor,
- Gilbert’s syndrome,
- drugs (e.g. ecstasy),
- Overdose of paracetamol.
Obesity and alcohol-independent fatty liver can lead to cirrhosis and jaundice.
3. Posthepatic jaundice (also known as occlusive jaundice) – there is an obstacle that blocks the bile duct and prevents the flow of bile into the gallbladder and small intestine. In this case, the urine becomes dark, while the stool becomes lighter.
Causes of posthepatic jaundice include gallstones, pancreatitis, pancreatic tumor and gallbladder tumor.
Jaundice caused by a tumor often means steady deterioration because the duct remains blocked due to the mechanical narrowing caused by the tumor.
A high-fat diet can lead to elevated cholesterol, which increases the risk of gallstones.
Cholestatic jaundice is defined as the inability of bile to pass from the liver to the duodenum (duodenum).
The source of interference may be in the main bile ducts (extrahepatic cholestasis) or inside the liver (intrahepatic cholestasis).
Morphologically, cholestasis is characterized by the accumulation of bile in the liver cells and bile ducts.
The symptoms are usually itching and the gradual appearance of jaundice.
The term “occlusive jaundice” indicates cholestasis of extrahepatic origin.
In pregnancy, this disorder can occur in women due to certain diseases, such as: hepatitis (A, B, C, D, E), cirrhosis of the liver, intrahepatic pregnancy cholestasis, gallstones and preeclampsia.