What Is Liver Fibrosis? Symptoms and Causes
Liver fibrosis is a complication of liver disease that causes the healthy tissue in your liver to be replaced by scar tissue. This scarring prevents your liver from functioning properly — if left untreated, it can lead to permanent liver damage (cirrhosis) and other health complications.1
Learning what causes liver fibrosis and what symptoms to look out for can help you get the treatment you need. Fortunately, liver fibrosis that’s diagnosed and treated early is often reversible.2
What Is Liver Fibrosis?
Liver fibrosis is caused by inflammation or injury, typically from an infection or other condition that damages the liver. As a result, your liver cells begin creating collagen and other proteins to heal themselves.3
If you have a chronic infection or disease that continues to damage the liver, your cells try to keep up with repairing the tissue. Over time, this continuous repair process causes collagen to build up, creating scar tissue or fibrosis. Scar tissue can also change your liver’s structure, blocking blood flow and limiting the oxygen supply — as a result, healthy liver cells continue to die and be replaced with fibrotic tissue.
If the underlying cause of inflammation isn’t treated, liver fibrosis can progress into cirrhosis. This is a serious condition that causes permanent liver scarring and damage. Cirrhosis eventually leads to liver failure and other health complications.4
What Causes Liver Fibrosis?
Any condition that causes liver inflammation and damage can eventually lead to scarring. The most common causes of liver fibrosis are:5
- Nonalcoholic fatty liver disease (NAFLD)
- Alcoholic liver disease
- Chronic (long-term) infection with hepatitis B or hepatitis C
Other less common causes of liver fibrosis include:
- Extremely high iron levels (hemochromatosis)
- Autoimmune hepatitis caused by your immune system attacking your liver
- A blockage in the bile duct caused by some diseases, including primary sclerosing cholangitis or primary biliary cholangitis
- Taking certain medications, including antibiotics, anti-fungal agents, and chemotherapy treatments for cancer6
- Congestive heart failure that’s caused increased pressure and decreased blood flow to the liver
Liver fibrosis may develop quickly or take several years. Even if you have NAFLD or a hepatitis infection, it doesn’t mean you’ll go on to develop fibrosis. Some people may never progress to advanced stages and can reverse their fibrosis, while others may progress quickly and require more intensive treatment.
Risk Factors for Liver Fibrosis
There are certain risk factors that increase your chances of developing liver fibrosis. Some of these you can control, while others you can’t. Knowing your risks can help you make healthier lifestyle choices to avoid liver damage and long-term complications.
Risk factors for liver fibrosis include:7,8
- Male sex
- Having a chronic (long-term) viral infection or disease
- Co-infection with both viral hepatitis and human immunodeficiency virus (HIV)
- Low levels of certain immune cells, known as CD4 T cells, caused by HIV infection
- Excessive alcohol consumption, which increases your risk of liver disease
- Being overweight or obese
- Imbalance of cholesterol levels (dyslipidemia)
- Smoking tobacco
- Untreated or uncontrolled diabetes
Stages of Liver Fibrosis
There are several staging systems used to measure the extent of liver fibrosis. If your doctor believes you have fibrosis, they may perform a biopsy. This procedure involves taking a small piece of liver tissue using a large needle. The tissue is then looked at under a microscope to determine the cause of the fibrosis and how severe it is.
Your pathologist (a doctor who specializes in looking at tissues to diagnose diseases) may use one of many scales to stage your liver fibrosis.9 While each scale rates fibrosis slightly differently, they all take into account how the scar tissue has affected the portal vein. This vein is responsible for carrying blood from your intestines to your liver. Many of the scales also measure how much scarring there is by counting the number of fibrous bands in the tissue sample, known as septa.
Batts-Ludwig Scale
The Batts-Ludwig scale is one of the most common scales used in the United States and ranks liver fibrosis on a scale from 0 to 4 — 0 meaning there’s no fibrosis and 4 being cirrhosis. This scale takes into account the presence of septa and how they affect the liver’s veins and structure.9 This system also ranks liver inflammation from 1 to 4.
Metavir Scale
The Metavir scale creates a score using two scales based on how much fibrosis and inflammation or activity there is. The higher the score, the worse the fibrosis and inflammation.10
Activity (A) is measured on a scale from A0 to A3:
- A0: No inflammation
- A1: Mild inflammation
- A2: Moderate inflammation
- A3: Severe inflammation
Fibrosis (F) is measured on a scale from F0 to F4:
- F0: No fibrosis
- F1: Portal fibrosis without septa
- F2: Portal fibrosis with some septa
- F3: Several septa without cirrhosis
- F4: Cirrhosis
Symptoms of Liver Fibrosis
In the early stages of liver fibrosis, most people don’t experience any symptoms. They often aren’t noticeable until liver fibrosis progresses and more liver damage occurs. One study suggests that around 7 percent of the global population has liver fibrosis, but they’re unaware because they haven’t experienced any symptoms.11
As liver fibrosis progresses, your liver can’t work as well as it used to. Scar tissue blocks blood flow, preventing your liver from filtering toxins. It also has a harder time healing and creating new, healthy tissue.
Symptoms you may begin to experience with mild to moderate liver fibrosis include:5
- Pain or discomfort in your upper right abdomen
- Nausea and appetite loss
- Unexplained weight loss
- Feeling weak and/or fatigued
Once liver fibrosis has progressed to cirrhosis, you may begin to experience other symptoms, such as:5
- Bleeding or bruising easily
- Swelling in your abdomen, legs, feet, or ankles caused by fluid buildup
- Extremely itchy skin
- Increased sensitivity to certain medications, leading to unwanted side effects
- Trouble thinking and concentrating
- Confusion, changes in your personality, or memory loss
- Changes in your sleep patterns
- Yellowing of your skin or eyes (jaundice)
- Dark-colored urine
How Is Liver Fibrosis Diagnosed?
If your doctor suspects you have liver fibrosis or if you have chronic liver disease, you’ll likely undergo testing to check for any scarring and damage. In addition to a liver biopsy, your doctor may order additional bloodwork and imaging tests.
Physical Exam and Bloodwork for Liver Fibrosis
Your doctor will begin by taking your medical history and performing a physical exam. They’ll ask questions about your symptoms and determine what your risk of liver fibrosis is, particularly if you have one or more associated risk factors. During the physical exam, they’ll check for any signs of jaundice or swelling in your legs or abdomen.12
Bloodwork will be done to evaluate for the type of liver disease, how severe the damage is, any associated problems including in other organs, and for any underlying causes that can be treated or improved. Cirrhosis can cause easy bleeding but also an increased risk of clotting, because the liver can’t make the many proteins it did before. If your doctor is unsure of what may be causing your liver fibrosis, they can run tests to check for:
- Increased liver enzyme levels: Including alanine transaminase (ALT), alkaline phosphatase (ALP), and aspartate transaminase (AST)
- Increased bilirubin levels: A substance made when your body breaks down old red blood cells
- Platelet levels: Low platelet levels are responsible for easy bleeding and bruising associated with cirrhosis
- Liver function tests such as albumin, INR, and bilirubin – these assess how the liver is functioning.
- Hepatitis B or C infection: Tests for these most common hepatitis viruses, which can cause liver inflammation and fibrosis
- Other blood tests can help assess how much scarring (fibrosis) your liver has, delaying or sometimes making liver biopsy unnecessary
- Other blood tests are often done to check for the underlying cause of chronic liver disease and fibrosis
Imaging Tests for Liver Fibrosis
Imaging tests help your doctor visualize any changes in the shape, size, and stiffness of your liver. The more fibrosis you have, the stiffer your liver is. These tests not only help to diagnose liver fibrosis — they’re also used to monitor if your scarring is getting better or worse over time.
Imaging tests used to diagnose and monitor liver fibrosis include:12
- Computed tomography (CT) scans: Use x-rays to create detailed images of your liver
- Magnetic resonance imaging (MRI) scans: Use extremely strong magnets and radio waves to create 3-dimensional (3D) images of your liver
- Ultrasound: Uses soundwaves to create real-time images of your liver
- Transient elastography: A specialized ultrasound used to measure the stiffness of your liver; it also measures liver fat
Complications of Liver Fibrosis
Once liver fibrosis progresses to cirrhosis, your liver can no longer function properly. If there’s too much damage, you may have end-stage liver disease or liver failure and require a transplant.4
Other complications include:13
- Increased risk of bacterial infections, including pneumonia and urinary tract infections (UTIs)
- Increased risk of liver cancer
- High blood pressure in the portal vein (portal hypertension), which can cause swelling, enlarged veins, and the buildup of toxins in your blood
- Bone thinning (osteoporosis) and other bone diseases
- Difficulties processing and absorbing nutrients from food, leading to malnutrition
- Type 2 diabetes
- Enlarged spleen (splenomegaly)
- Fluid buildup in the abdomen (ascites). This can get infected.
- Gastrointestinal bleeding
- Kidney dysfunction or failure
Preventing Liver Fibrosis and Cirrhosis
If you’ve been diagnosed with liver fibrosis, there are steps you can take to prevent it from progressing to cirrhosis. The Mayo Clinic recommends:13
- Avoiding alcohol
- Eating a healthy diet high in whole grains, lean proteins, fruits, and vegetables while limiting fatty foods
- Taking steps to reduce your risk of hepatitis infection, such as practicing safe sex
- Reaching and maintaining a healthy weight and exercise to avoid further damage to your liver
Resources for Living with Liver Fibrosis
If you or a loved one is living with liver fibrosis or cirrhosis, there are resources available to help you better manage the condition and connect with others.
- Resources — American Liver Foundation
- Liver Disease Resources — UC San Diego Health
- Viral Hepatitis and Liver Disease: Resources — U.S. Department of Veterans Affairs
- American Association for the Study of Liver Diseases (AASLD) – Patient information at https://www.aasld.org/patient-resources
Sources
- Bataller R, Brenner DA. Liver fibrosis. J Clin Invest. 2005;115(2):209-218.
- American Liver Foundation. How Liver Diseases Progress. February 1, 2023. Accessed from: https://liverfoundation.org/about-your-liver/how-liver-diseases-progress/
- Roehlen N, Crochet E, Baumert TF. Liver fibrosis: Mechanistic concepts and therapeutic perspectives. Cells. 9(4):875.
- National Institute of Diabetes and Digestive and Kidney Diseases. Definition & Facts for Cirrhosis. March 2018. Accessed from: https://www.niddk.nih.gov/health-information/liver-disease/cirrhosis/definition-facts
- National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & Causes of Cirrhosis. March 2018. Accessed from: https://www.niddk.nih.gov/health-information/liver-disease/cirrhosis/symptoms-causes
- Clinical course and diagnosis of drug induced liver disease. In: LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet]. National Institute of Diabetes and Digestive and Kidney Diseases. 2019.
- U.S. Department of Veterans Affairs. Assessment of Liver Fibrosis. October 23, 2018. Accessed from: https://www.hepatitis.va.gov/hcv/liver-fibrosis.asp#S1X
- de Torres M, Poynard T. Risk factors for liver fibrosis progression in patients with chronic hepatitis C. Ann Hepatol. 2003;2(1):5-11.
- Dhingra S, Ward SC, Thung SN. Liver pathology of hepatitis C, beyond grading and staging of the disease. World J Gastroenterol. 2016;22(4):1357-1366.
- Cox-North PP. Evaluation and Staging of Liver Fibrosis. Hepatitis C Online. April 19, 2021. Accessed from: https://www.hepatitisc.uw.edu/go/evaluation-staging-monitoring/evaluation-staging/core-concept/all
- Ginès P, Graupera I, Lammert F, et al. Screening for liver fibrosis in the general population: A call for action. Lancet Gastroenterol Hepatol. 2016;1(3):256-260.
- National Institute of Diabetes and Digestive and Kidney Diseases. Diagnosis of Cirrhosis. March 2018. Accessed from: https://www.niddk.nih.gov/health-information/liver-disease/cirrhosis/diagnosis
- Mayo Clinic. Cirrhosis. February 6, 2021. Accessed from: https://www.mayoclinic.org/diseases-conditions/cirrhosis/symptoms-causes/syc-20351487