The diseases that lead to cirrhosis do so because they injure and kill liver cells, and the inflammation and repair that is associated with the dying liver cells causes scar tissue to form.
The liver cells that do not die multiply in an attempt to replace the cells that have died. This results in clusters of newly-formed liver cells (regenerative nodules) within the scar tissue. There are many causes of cirrhosis; they include chemicals (such as alcohol, fat, and certain medications), viruses, toxic metals (such as iron and copper that accumulate in the liver as a result of genetic diseases), and autoimmune liver disease in which the body's immune system attacks the liver.
In cirrhosis, the relationship between blood and liver cells is destroyed. Even though the liver cells that survive or are newly-formed may be able to produce and remove substances from the blood, they do not have the normal, intimate relationship with the blood, and this interferes with the liver cells' ability to add or remove substances from the blood. In addition, the scarring within the cirrhotic liver obstructs the flow of blood through the liver and to the liver cells. As a result of the obstruction to the flow of blood through the liver, blood "backs-up" in the portal vein, and the pressure in the portal vein increases, a condition called portal hypertension. Because of the obstruction to flow and high pressures in the portal vein, blood in the portal vein seeks other veins in which to return to the heart, veins with lower pressures that bypass the liver. Unfortunately, the liver is unable to add or remove substances from blood that bypasses it.
It is a combination of reduced numbers of liver cells, loss of the normal contact between blood passing through the liver and the liver cells, and blood bypassing the liver that leads to many of the manifestations of cirrhosis.
It is a combination of reduced numbers of liver cells, loss of the normal contact between blood passing through the liver and the liver cells, and blood bypassing the liver that leads to many of the manifestations of cirrhosis.
A second reason for the problems caused by cirrhosis is the disturbed relationship between the liver cells and the channels through which bile flows. Bile is a fluid produced by liver cells that has two important functions: to aid in digestion and to remove and eliminate toxic substances from the body. The bile that is produced by liver cells is secreted into very tiny channels that run between the liver cells that line the sinusoids, called canaliculi. The canaliculi empty into small ducts which then join together to form larger and larger ducts. Ultimately, all of the ducts combine into one duct that enters thesmall intestine. In this way, bile gets to the intestine where it can help with the digestion of food. At the same time, toxic substances contained in the bile enter the intestine and then are eliminated in the stool.
In cirrhosis, the canaliculi are abnormal and the relationship between liver cells and canaliculi is destroyed, just like the relationship between the liver cells and blood in the sinusoids. As a result, the liver is not able to eliminate toxic substances normally, and they can accumulate in the body.
To a minor extent, digestion in the intestine also is reduced.
In cirrhosis, the canaliculi are abnormal and the relationship between liver cells and canaliculi is destroyed, just like the relationship between the liver cells and blood in the sinusoids. As a result, the liver is not able to eliminate toxic substances normally, and they can accumulate in the body.
To a minor extent, digestion in the intestine also is reduced.
Patients with cirrhosis may have few or no symptoms and signs of liver disease. Some of the symptoms may be nonspecific, that is, they don't suggest that the liver is their cause. Some of the more common symptoms and signs of cirrhosis include:
- Yellowing of the skin (jaundice) due to the accumulation of bilirubin in the blood
- Fatigue
- Weakness
- Loss of appetite
- Itching
- Easy bruising from decreased production of blood clotting factors by the diseased liver.
Patients with cirrhosis also develop symptoms and signs from the complications of cirrhosis that are discussed next.
Edema and ascites
Bleeding from esophageal varices
Hepatic encephalopathy
Spontaneous bacterial peritonitis (SBP)
Hepatorenal syndrome
Hepatopulmonary syndrome
Hypersplenism
Liver cancer (hepatocellular carcinoma)
The most common symptoms and signs of primary liver cancer are abdominal pain and swelling, an enlarged liver, weight loss, and fever. In addition, liver cancers can produce and release a number of substances, including ones that cause an increased in red blood cell count (erythrocytosis), low blood sugar (hypoglycemia), and high blood calcium (hypercalcemia ).Continue.
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