What is liver fibrosis?
Liver fibrosis is scarring of the liver. Your liver is the biggest internal organ. It has many jobs, including aiding digestion, storing energy, making blood-clotting components, and removing waste and microorganisms. The liver is also able to regenerate—or regrow—itself to repair damage.
Normally, when the liver has been harmed, it makes new cells and attaches them to its internal connective tissue structure. This structure is called the extracellular matrix (ECM). The new cells replace the old ones that have died. However, this doesn’t work the way it should when the liver is diseased or the injury is continuous or severe. Instead, the attempts at repair cause a buildup of ECM tissue in place of functioning liver cells. This buildup is scarring. Scars are fibrous tissue, hence the name fibrosis. Another name for liver fibrosis is hepatic fibrosis.
Liver fibrosis is not a specific condition, but rather a symptom of another liver problem. In the United States, the most common conditions that result in liver fibrosis are alcoholism, chronic hepatitis C, and nonalcoholic fatty liver disease (NAFLD). Having these conditions puts you at risk of developing liver fibrosis.
Liver fibrosis causes no symptoms itself. Doctors can find signs of liver fibrosis with blood tests and imaging exams. If they find it early, it’s possible that liver fibrosis is curable or reversible. However, if it remains undetected and the damage continues, it can progress to cirrhosis. The difference between liver fibrosis vs. cirrhosis is cirrhosis is permanent scarring that is irreversible. The liver becomes smaller and mostly consists of hard scar tissue. Once cirrhosis develops, symptoms and problems can appear.
Liver fibrosis treatment relies on treating the underlying cause. This may include stopping alcohol use, using antiviral drugs, or losing weight. In some cases, treatment of the cause can even help in advanced liver fibrosis stages. The liver will slowly heal itself with time.
Left untreated, fibrosis and cirrhosis can lead to liver failure. Regular medical care and blood tests can help spot changes in your liver function before it becomes severe.
What are the symptoms of liver fibrosis?
The scarring of liver fibrosis can interfere with the liver’s ability to work efficiently. However, fibrosis itself doesn’t cause any symptoms. You can have liver fibrosis and not know it. Fortunately, doctors can find signs of liver fibrosis with blood tests called liver function tests (LFTs). Most people get LFTs for routine physical exams. It’s also possible to see liver fibrosis on imaging exams. Doctors may notice this if you have imaging exams for some other condition. Seeing your doctor regularly for an annual exam can help uncover potential liver problems while there is still time to address them.
Serious symptoms that might indicate a serious condition
If fibrosis progresses to cirrhosis, common symptoms can include:
- Easy bruising and bleeding
- Yellowing of the skin and eyes (jaundice)
Liver cirrhosis is a serious disease that can lead to life-threatening complications. Seek immediate medical care for symptoms of cirrhosis.
What causes liver fibrosis?
Liver fibrosis occurs when the liver is diseased or sustains chronic or severe injury. As the liver tries to repair itself by making new cells, it isn’t able to do so. Instead, the dead liver cells are replaced by fibrous tissue—or scar tissue. This scar tissue eventually prevents the liver from functioning normally.
Liver fibrosis is a symptom of several underlying conditions. In the United States, the most common causes are:
- Alcohol abuse. The liver breaks down alcohol you drink so your body can get rid of it. The process produces harmful byproducts that damage liver cells. The more alcohol you drink, the worse the damage.
- Chronic hepatitis C infection. The hepatitis C virus (HCV) infects the liver, causing damage and inflammation. Most people with HCV don’t have symptoms for several years after becoming infected. As a result, it’s common to have liver problems, including fibrosis, at diagnosis. Fortunately, effective treatments are available.
- Nonalcoholic fatty liver disease (NAFLD). NAFLD is a buildup of fat in the liver that can cause inflammation and damage, leading to fibrosis. It is not related to alcohol use. Instead, it tends to affect people with obesity and conditions related to obesity, such as type 2 diabetes.
Other potential underlying causes of liver fibrosis include bile duct blockages, autoimmune diseases, hereditary metabolic disorders, conditions that cause decreased blood flow to the liver, and certain medications. There is also a congenital form of liver fibrosis that is present at birth.
What are the risk factors for liver fibrosis?
A number of factors increase the risk of developing liver fibrosis including:
- Abusing alcohol and drinking it in excess
- Being obese with fat distribution mainly in the abdomen
- Having certain hereditary conditions, such as alpha-1 antitrypsin deficiency, hemochromatosis, and Wilson disease
- Having certain medical conditions, including chronic hepatitis C infection and type 2 diabetes
- Taking certain drugs, such as amiodarone, corticosteroids, isoniazid, methotrexate and methyldopa
Reducing your risk of liver fibrosis
You may be able to lower your risk of liver fibrosis by:
- Controlling blood sugar levels and blood pressure
- Limiting or stopping alcohol consumption and getting help for alcohol abuse
- Losing weight, which is the most effective treatment for NAFLD
- Maintaining a healthy body weight with a healthy diet and exercise
Seeing your doctor regularly will help identify liver fibrosis in the early stages. In general, the earlier you find potential liver problems, the more likely it will be to reverse any damage.
What are the stages of liver fibrosis?
Liver fibrosis is diagnosed by examining abnormal changes to the microscopic structure of tissue obtained by liver biopsy. One of the classic scoring systems is METAVIR. It has five stages:
- F0: no fibrosis (scarring); there are no signs of liver cell death (necrosis) or scarring despite liver inflammation (hepatitis)
- F1: portal fibrosis, or mild fibrosis where there are areas (foci) of necrosis and scarring involves the small and medium branches of the portal vein (carrying blood from the small intestine); liver structure and function are still normal
- F2: periportal fibrosis, or moderate fibrosis with increasing necrotic foci, scarring, and impaired function
- F3: bridging fibrosis, or severe fibrosis where scarring has disrupted normal blood flow through the liver and function is further impaired
- F4: cirrhosis, which is permanent scarring and irreversible loss of liver function
How is liver fibrosis treated?
There is no specific treatment of liver fibrosis. Since it is a symptom of another liver problem, the most effective way to treat it is to address the underlying condition. Removing the cause of the liver damage will stop the fibrosis and allow the liver to heal. In the early stages, the damage is usually reversible. However, even advanced fibrosis (e.g., stage F3) can show improvement once the injury ceases.
For the most common causes, treatment involves stopping all alcohol consumption, treating hepatitis C virus infection with antivirals, and losing weight to resolve NAFLD. The less common causes also have therapies that can help stop liver damage.
When fibrosis progresses to cirrhosis, liver transplantation may be an option.
What are the potential complications of liver fibrosis?
The main complication of liver fibrosis is progression to cirrhosis. Cirrhosis can lead to life-threatening complications including:
- Hepatic encephalopathy, which is a buildup of toxins that affects the brain and can lead to coma and death
- Liver failure and liver cancer