Causes
Normally, large amounts of blood flow each minute through the liver, which
may be thought of as the body's chemical processing plant. The liver breaks
down old, inefficient red blood cells in a process called hemolysis.
This releases large amounts of bilirubin. The liver also manufactures the other
components of bile.
Bile is a greenish-yellow fluid secreted by the liver that contains cholesterol,
bile salts and waste products such as bilirubin. The bilirubin leaves the liver
via the bile ducts to be stored in the gallbladder directly underneath. It's
then slowly released into the intestine from the gallbladder. There it helps
digest food, then exits the body in the stool.
Too much bilirubin can be toxic and can cause jaundice. Therefore,
it's important to excrete it as fast as it's produced. There are three basic
ways this process can go wrong:
- The liver itself can be temporarily or permanently damaged, reducing its
ability to metabolize bilirubin (mix it with bile) and move it into the gallbladder.
- The gallbladder or its bile ducts can become blocked, preventing excretion
of bilirubin into the intestine. Bilirubin will then back up into the liver
and then into the bloodstream.
- Any condition that leads to very rapid destruction of red blood cells can
create too much bilirubin for even a healthy liver to handle. Again, the excess
is carried into the bloodstream.
Causes of jaundice due to poor liver function include:
- Viral hepatitis - Hepatitis A, B, C, D, and E can all cause temporary
liver inflammation. Types B and C can also cause chronic, lifelong inflammation.
- Drug-induced hepatitis - This may be caused by alcohol, the common
antibiotic azithromycin, anti-cancer drugs, chlorpropamide, corticosteroids,
and occasionally antidepressants, testosterone, oral contraceptives, acetaminophen,
and many other drugs.
- Autoimmune hepatitis - In this condition, the body's immune system
attacks its own liver cells. Autoimmune hepatitis is more common in people
and families with other autoimmune diseases, such as lupus, thyroid disease,
diabetes, or ulcerative colitis. Primary biliary cirrhosis is another autoimmune
condition of the liver and involves inflammation of the bile ducts.
- Alcoholic liver disease - This involves damage to the liver caused
by excessive, long-term consumption of alcohol.
- Gilbert's syndrome - This harmless inherited condition is quite common,
affecting about 2% of the population. Minor defects in the liver's metabolism
of bilirubin cause jaundice to appear in times of stress, exercise, hunger,
or infection.
Causes of jaundice due to obstruction (blockage) include:
- Gallstones - Formed in the gallbladder, gallstones can block the
bile ducts, preventing bile (and bilirubin) from reaching the intestine. Sometimes,
the bile ducts may become infected and inflamed.
- Cholestasis of pregnancy - Abdominal pressure closes ducts between
the liver and gallbladder, or between the gallbladder and intestine. Jaundice
is common during pregnancy.
- Tumors - These may be in the liver, pancreas, or gallbladder. They
are occasionally responsible for obstruction.
Causes due to excessive red blood cell destruction (hemolysis):
- Malaria - The liver destroys red blood cells infected with the parasite.
- Hemolytic anemia - This includes conditions such as
sickle cell disease and thalassemia. It may also be an autoimmune condition.
- Newborn jaundice - This condition is found in many newborn babies.