Cirrhosis is the term used to describe a diseased liver that has been severely scarred, usually due to many years of continuous injury. The liver is a large organ (weighing about three pounds) that is located in the right upper abdomen, beneath the rib cage.
It performs many functions that
are essential to life including:
- Cleansing toxins from the blood
- Metabolising medications
- Producing blood proteins that are essential for normal blood clotting
- Manufacturing albumin, a protein that is required for maintaining normal fluid balance in the body
- Producing bile that is required for digestion of dietary fat.
The liver is able to repair itself when it has been injured as a result of certain diseases like hepatitis. The process of healing involves the creation of scar tissue. Thus, repeated or continuous injury to the liver (such as occurs with heavy alcohol use) can cause significant scarring in the liver. The body is able to tolerate a partially scarred liver without serious consequences but eventually, the scarring can become so severe that the liver is no longer able to perform its normal functions.
Causes
Cirrhosis has many causes. In most cases, the cause of cirrhosis can be identified. In about 5 percent of patients, it is not possible to identify the cause; such patients are said to have idiopathic cirrhosis.
Some of the most common causes of cirrhosis include:
- Longstanding alcohol abuse
- Chronic hepatitis (B or C)
Other causes include:
- Non-alcoholic steatohepatitis or NASH (a condition in which fat and scar tissue
accumulate in the liver)
- Hemochromatosis (a condition in which there is too much iron in the body)
- Autoimmune hepatitis (a condition in which the body’s immune system recognises the liver as foreign)
- Wilson’s disease (a rare disease
of cop per metabolism)
Signs and symptoms —
People with cirrhosis may have symptoms related to the underlying cause of the liver disease, symptoms directly related to the cirrhosis, or no symptoms at all.
Many people with early cirrhosis have few or no symptoms. One common symptom is fatigue.
As the cirrhosis progresses, symptoms develop because the liver is no longer able to perform its normal functions. The rate at which symptoms develop depends upon the underlying liver disease, treatments used, and individual factors. In some patients, symptoms do not develop for years, even after the liver has become cirrhotic. In others, symptoms never develop because the cause of the liver disease is eliminated.
Scarring makes it difficult for blood to flow through the liver. As a result, veins in other parts of the body outside of the liver become abnormally expanded. Abnormally expanded blood vessels are referred to as varices.
One place where varices are commonly found is in the esophagus, the swallowing tube connecting the mouth with the stomach. When the pressure in the varices reaches a certain level, the varices can burst, which can cause massive bleeding (known as variceal bleeding).
Body fluids accumulate as a result of liver scarring and a decreased ability to manufacture blood proteins. Fluid is typically seen in the legs (oedema) and abdomen (ascites) and sometimes in the lung (pleural effusion).
Ascites causes the abdomen to enlarge, which can cause shortness of breath and a feeling of fullness. The ascitic fluid provides an environment where bacteria can grow, increasing the risk of infection.
Patients with cirrhosis are at risk of easy bruising and bleeding. This is a result of two problems:
First, levels of the blood cells
(platelets) that are essential to form clots can be severely decreased.
Second, certain blood proteins made by the liver (called clotting factors) are decreased.
Once bleeding starts (such as with variceal bleeding), it can be severe.
Hepatic encephalopathy is a condition that develops when the liver is unable to break down toxins normally found in the bloodstream, such as ammonia. In this condition, confusion or even coma are caused by toxins that build up in the blood. In the early stages, a patient may experience mild symptoms, such as difficulty sleeping or sleeping too much. Advanced hepatic encephalopathy can cause confusion, delirium, and even coma.
Hepatic encephalopathy can develop suddenly and may become a medical emergency. Hospitalisation is usually required for initial treatment of severe confusion or coma.
Patients with cirrhosis have decreased function of their immune system and are therefore at increased risk of bacterial infections. Malnutrition is common in patients with cirrhosis. Malnutrition can cause loss of muscle in various areas of the body. Many patients with advanced cirrhosis have jaundice. The degree of jaundice can be measured with a laboratory value called the total bilirubin. Normally, the total bilirubin in blood should be less than 1 mg/dL. Once the bilirubin reaches 3 mg/dL, the whites of the eyes become yellow. Higher levels often causes yellowing of the skin.
People with cirrhosis are at increased risk for developing liver cancer (hepatocellular carcinoma). The risk depends in part upon the underlying cause of cirrhosis.
Diagnosis
Several tests are used to confirm the diagnosis of cirrhosis and to determine the underlying cause. Other tests are useful for determining the severity of cirrhosis and for monitoring complications.
Liver biopsy — The best way to confirm the diagnosis of cirrhosis is by obtaining a small piece of tissue from the liver with a special needle (a liver biopsy).
Imaging tests — A variety of imaging tests, such as an ultrasound scan, CT scan, or MRI, can suggest that a person has cirrhosis. These tests describe the appearance of the liver or related complications, such as varices or ascites. However, these tests are not used to diagnose cirrhosis, and cannot replace a liver biopsy.
Physical examination — Patients with cirrhosis may have several physical signs of their condition. These include one or more of the following:
- Jaundice (yellow skin and whites of the eyes).
- A distended, fluid-filled abdomen (ascites).
- An enlarged liver or spleen
- Oedema (swelling, mostly
of the legs).
- Enlarged breast tissue (in men).
- Redness of the palms (palmar erythema) .
Laboratory tests — Laboratory tests often reveal abnormal blood chemistries, low protein counts, low platelet counts, and increased bilirubin. However, these tests may be normal in people with early cirrhosis. Laboratory testing can often reveal the specific underlying cause of cirrhosis.
There are several other laboratory tests that are being developed that can allow for the diagnosis of cirrhosis without a liver biopsy ( eg liver fibroscan). They are not yet widely available.
Next month: Treatment
(The writer is a Consultant Physician, Gastroenterologist & Hepatologist )
|
E-mail
