Chronic liver disease
Chronic liver disease is any type of long-term liver disease that lasts for at least six months. There are many types of chronic liver diseases, but the most common include cirrhosis of the liver, hepatocellular carcinoma (the most prevalent kind of liver cancer), and chronic liver inflammation (chronic hepatitis). Chronic liver disease is the 12th leading cause of death in the United States, killing around 38,000 people every year.
Definition & Facts
The liver is the largest internal organ of the body and it plays many roles, including protein production, blood clotting, food digestion, energy storage, and poison or toxin removal. Chronic liver disease refers to any disease that damages the liver and its ability to regenerate over time and leads to cirrhosis and fibrosis. Chronic liver disease lasts over a period of six months or longer unlike acute liver disease that may occur in just one or two days.
Chronic liver disease refers to a wide range of conditions, most of which are caused by excessive alcohol consumption, hepatitis B or hepatitis C, certain drugs like high amounts of acetaminophen, or non-alcoholic fatty liver disease. Diagnosis and treatment of chronic liver disease depends on the specific cause.
Symptoms & Complaints
Many patients also experience unexplained weight loss, weakness, and fatigue. Cirrhosis, or scarring of the liver that is usually caused by obesity, hepatitis, or excessive alcohol consumption can lead to worsening symptoms as the disease progresses. These may include muscle loss, easy bruising, fluid buildup in the abdomen, vomiting blood that is usually caused by bleeding in the esophagus, gallstones, spider-like veins, confusion due to toxin buildup, and acute kidney failure.
Advanced liver disease can lead to liver failure in which the liver is severely damaged and unable to function. Liver failure usually occurs over months or years and it is usually caused by cirrhosis, alcohol, or hepatitis, but acute liver failure can occur in just two days due to acetaminophen overdose or a reaction to some prescriptions or herbal medicines. Liver failure can cause jaundice, bleeding, sleepiness, a swollen abdomen, disorientation, and coma.
Chronic liver disease may have many causes depending on the condition. Many forms of liver disease are caused by viral infections including hepatitis B and hepatitis C, both of which are infectious diseases that may be transmitted by exposure to infectious bodily fluids or blood through intravenous drug use and sex (sexually transmitted disease).
Liver disease may also be caused by acetaminophen, alcohol, or some drugs like methotrexate, but these cases are rare. Alcoholic liver diseases commonly cause chronic liver disease, scarring the liver from heavy alcohol use. Other potential causes of liver disease include: non-alcoholic fatty liver disease (NAFLD), hemochromatosis (iron overload), Wilson's disease, autoimmune hepatitis, and inherited diseases like cystic fibrosis and Alpha 1-antitrypsin deficiency.
NAFLD is the most common liver disorder in developed countries like the United States and it occurs when fat is deposited in the liver for reasons other than alcohol use. This condition is related to metabolic syndrome and insulin resistance and it occurs in about 80% of obese people. The prevalence of NAFLD in the U.S. is estimated at 30%.
Diagnosis & Tests
If hepatitis B or hepatitis C infection is suspected, a serum or blood test may be ordered to detect viral antigens or proteins produced by the virus, or antibodies produced by the body to fight infection. Hepatitis B is most often diagnosed by testing for the hepatitis B surface antigen (HBsAg). People who are HBsAg positive for at least six months are hepatitis B carriers and may have long-term effects like liver inflammation.
Hepatitis C may be diagnosed using the HCV antibody enzyme immunoassay, recombinant immunoblot assay, or the quantitative HCV RNA PCR tests. Cirrhosis is usually detected first during a routine blood test that measures liver function. Excessive bilirubin in the blood indicates that red blood cells have broken down and the patient may have some level of liver damage.
A physician may also order a kidney function blood test to check for creatinine. Other tests to diagnose chronic liver disease may include imaging tests such as a magnetic resonance elastography to check for hardening of the liver. This test utilizes MRI technology. An ultrasound or a CT scan may also be performed. Biopsies may be taken of the liver to identify the severity and cause of the damage.
Treatment & Therapy
Treatment for chronic liver disease depends on the cause of the disease. The underlying cause of the disease is usually addressed first. In the case of excessive alcohol consumption, a physician will likely recommend treatment for alcohol dependency as any amount of alcohol will be toxic to the liver. Weight loss is recommended for patients with liver damage caused by non-alcoholic fatty liver disease.
Patients who have chronic liver disease caused by hepatitis B or C are usually treated with medication to control the virus. Treatment for hepatitis B may last 6 to 12 months, depending on the medication and virus genotype. There are currently seven medications on the market to treat hepatitis B infection and minimize liver damage, including lamivudine, tenofovir, entecavir, and adefovir. Hepatitis C is treated with several medications. Sofosbuvir, interferon, and ribavirin combined are effective in about 90% of people with genotype 1, 4, 5, and 6 disease.
Prevention & Prophylaxis
Obesity is one of the most common causes of chronic liver disease and liver failure and can be prevented through regular exercise and eating a healthy diet. Not all risk factors can be avoided as many cases of liver disease are caused by inherited diseases or conditions.