Why is the liver important?
The liver is the largest internal organ in the body. It is impossible to live without the liver and its health plays a major role in quality of life. It performs hundreds of functions that are essential for life. Among the most fundamental functions are:
- Converts food into energy and chemicals necessary for life and growth.
- Acts as a filter to detoxify and excrete harmful substances such as alcohol and toxins.
- Processes medications absorbed from the digestive system and enables the body to use them effectively.
- Creates and exports important chemicals used by the body.
What causes chronic liver diseases?
There are more than 100 different liver diseases and liver disease severity falls on a continuum. The most common chronic liver diseases are hepatitis B, hepatitis C, Non-alcoholic Steatohepatitis (NASH), Alcoholic Liver Disease (ALD), and autoimmune diseases (autoimmune hepatitis, primary biliary cirrhosis, and primary sclerosing cholangitis).
How many people suffer from chronic liver disease?
According to the American Liver Foundation, 30 to 50 million people have liver disease, or more than 1 in 10 Americans. Even more shocking is that about 130 million Americans are at risk of developing liver disease. Worldwide, liver disease affects an estimated 500 million people.
Despite the potentially devastating effects of liver diseases, most people know little about them. Research shows that a majority of respondents believe that liver disease is primarily caused by alcohol abuse. The reality is that there are more than 100 different liver diseases that can be traced to a variety of causes related to family history, reactions to drugs and chemicals, social behavior and hygiene.
|Disease Etiology||At-Risk||Estimated Dx of Chronic Liver Disease
|Estimated Fibrotic Liver Disease (High Risk)|
|NAFLD/NASH||100 M||30 M||8.4 M|
|Alcohol-related||21 M||11 M||5.0 M|
|PBC, PSC||0.5 M||0.5 M||0.4 M|
|Genetic||0.5 M||0.4 M||0.3 M||Total||129 M||48.9 M||15.5 M|
What is the Economic and Societal Impact?
In the United States, over 64 million people are projected to have Non Alcoholic Fatty Liver Disease (NAFLD), with annual direct medical costs of about $103 billion ($1,613 per patient). https://www.ncbi.nlm.nih.gov/m/pubmed/27543837/
In 2019, NIH-supported research on chronic liver disease in the US was $851 million; the cost for liver cancer alone was $127 million. The NIH projects that the 2021 research funding for liver disease will be $819 million and $124 million for liver cancer. In 2018, the NIH recorded 1.8% prevalence of those with liver disease in the US. (https://report.nih.gov/categorical_spending.aspx)
Liver Health FAQs
Up to 50% of individuals with liver disease have no symptoms. The most common symptoms are non-specific and include fatigue or excessive tiredness, lack of drive, and occasionally itchy skin. Signs of liver disease that are more prominent are jaundice, or yellowing of the eyes and skin, dark urine, very pale or light-colored stool, bleeding from the GI tract, mental confusion, and retention of fluids in the abdomen.
The liver is the only organ in the body that is able to regenerate. Most organs in the body replace damage with scar tissue, but the liver is able to replace damaged tissue with new cells. However, the long-term complications of liver disease occur when regeneration is either incomplete or prevented by progressive development of scar tissue within the liver. This occurs when the damaging agent (e.g., a virus, drug, alcohol) continues to attack the liver and prevents complete regeneration. Severe scarring is called cirrhosis.
Varices are veins that are enlarged or swollen. The esophagus is the tube that connects the throat to the stomach. When enlarged veins occur on the lining of the esophagus, they are called esophageal varices.
Cirrhosis is the scarring of the liver caused by a long-term damaging agent, such as excessive alcohol intake or chronic viral hepatitis. The development of cirrhosis indicates late-stage liver disease and impairs function of the liver. People with cirrhosis often experience loss of appetite, nausea, vomiting, and weight loss.
With the exception of alcoholic liver disease, and liver disease found in starving populations, poor nutrition is generally not a cause of liver disease. It is much more likely that poor nutrition is a result, rather than a cause, of chronic liver disease.
The majority of patients with Hepatitis C are found to have a risk factor such as needle exposure, blood exposure, tattooing, body piercing, or sexual exposure which would allow for an exchange of blood or bodily fluids. A small percentage of patients have no identifiable risk factor and presumably acquired the disease through inadvertent exposure such as sharing a razor.