Bile is a fluid that is produced and released by the liver and stored in the gallbladder. It helps with digestion by breaking down fats into fatty acids, which is taken into the body by the gastrointestinal tract.
When the flow of bile is altered, it can lead to the buildup of bilirubin, a pigment produced by the liver and excreted from the body via bile. The reduced or blocked flow of bile from the liver can result in a liver disease known as cholestasis.
Types of Cholestasis
There are different types of cholestasis. These include:
Intrahepatic cholestasis is a type of cholestasis that originates within the liver. It can be caused by:
- Bacterial abscess in the liver
- Severe infections that have spread through the bloodstream (sepsis)
- Alcoholic liver disease
- Being fed exclusively through a vein (IV)
- Primary biliary cirrhosis
- Viral hepatitis
- Primary or metastatic liver cancer
- Primary sclerosing cholangitis
Intrahepatic cholestasis can also be caused by pregnancy, a condition known as obstetric cholestasis or intrahepatic cholestasis of pregnancy. This condition typically occurs during the late second trimester or the final trimester of pregnancy.
It can cause severe itching, especially on the hands and feet. Obstetric cholestasis does not often pose a severe risk for the mother’s health but may have complications for the fetus.
Extrahepatic cholestasis occurs outside the body and is caused by a physical barrier to the bile ducts. Gallstones, cysts and tumors are examples of blockages that can restrict bile from the liver. Other causes include:
- Narrowing of the bile duct (strictures)
- Presence of tumors which put pressure on the bile guts
- Pancreatic tumor or pseudocyst
- Primary sclerosing cholangitis
Certain medications can cause cholestasis, some of which include:
- Anabolic steroids
- Birth control pills
- Antibiotics such as ampicillin and other penicillins
Signs and Symptoms of Cholestasis
Cholestasis is a liver condition characterized by symptoms which include:
Dark urine occurs as a result of excess bilirubin secreted by the kidneys. Jaundice, the yellowing of the skin and eyes, also results from excess bilirubin deposited in the skin.
Stools are light-colored due to bilirubin restricted in the intestine and prevented from being ejected from the body via the stool. Stools may also contain too much fat (a condition known as steatorrhea) because the fat in food is not digested by bile in the intestine.
The skin itches due to the accumulation of bile products in the skin. Reduced bile in the digestive tract also means that vitamin D and calcium are poorly absolved.
Persistent cholestasis may lead to a deficiency of these nutrients and can have severe effects on the body. A lack of calcium, a nutrient responsible for the formation and maintenance of bones, may lead to loss of bone tissue.
Additionally, vitamin K, which is necessary for bone clotting, is poorly absorbed from the intestine, resulting in a tendency to bleed easily.
Other symptoms of cholestasis include loss of appetite, abdominal pain, vomiting and fever.
If cholestasis is suspected, the doctor will conduct a physical examination to confirm the diagnosis. These would include blood tests, ultrasounds or MRI, or liver biopsy in some cases.
Blood tests are typically done to measure the levels of gamma-glutamyl transpeptidase and alkaline phosphatase, two enzymes that are very high in people with cholestasis.
If the cause originates from within the liver, a liver biopsy may be done to establish a diagnosis.
Treating cholestasis must involve treating the underlying cause of the condition. For instance, if the diagnosis confirms that current medication is the cause of the condition, the doctor may recommend using a different drug.
In cases where obstructions like a tumor or gallstones are causing the buildup of bile, the doctor may recommend surgery. Obstetric cholestasis often resolves after delivery.