What happens when your liver stops working normally
Your liver is an organ about the size of a football that sits under your right rib cage. It filters your blood, breaks down harmful substances, makes proteins your body needs, and stores energy. When liver disease develops, the liver's cells become damaged and scarred, and it cannot do these jobs as well. Over time, the damage can become severe enough that your liver fails to function.
Liver disease is not one condition—it is a category of different diseases that damage liver cells in different ways. Some develop slowly over years. Others happen suddenly. Some are reversible if caught early; others cause permanent scarring called cirrhosis, which cannot be undone.
The key point is that your liver has a large reserve capacity. You can lose significant liver function before you feel sick. This is why many people have liver disease without knowing it, and why screening matters if you have risk factors.
Key Takeaways
- Liver disease damages liver cells and reduces the organ's ability to filter blood, break down toxins, and make proteins your body needs.
- The three main categories are fatty liver disease, viral hepatitis, and cirrhosis, though many other conditions can harm the liver.
- Early liver disease often causes no symptoms, so people with risk factors like heavy drinking, obesity, or hepatitis infection may not know they are affected.
- Cirrhosis is permanent scarring that cannot be reversed, but many forms of liver disease can be slowed or stopped if treated before cirrhosis develops.
The three main types of liver disease
Fatty liver disease means fat builds up inside liver cells. It comes in two forms: nonalcoholic fatty liver disease (NAFLD), which is linked to obesity and diabetes, and alcoholic fatty liver disease, which is caused by heavy drinking. Early-stage fatty liver disease usually has no symptoms and does not damage the liver. But in some people, the fat triggers inflammation that scars the liver over time.
Viral hepatitis is infection caused by a virus. Hepatitis A spreads through contaminated food or water and usually clears on its own. Hepatitis B and C spread through blood contact and can become chronic infections that damage the liver for decades. Hepatitis E is rare in the United States but common in other parts of the world. Each type is prevented or treated differently.
Cirrhosis is the end stage of chronic liver disease. Repeated injury—from alcohol, hepatitis, fatty liver disease, or other causes—triggers the liver to form scar tissue. Scar tissue replaces healthy liver cells and blocks blood flow through the organ. Once cirrhosis develops, it cannot be reversed, though treatment can slow its progress and manage complications.
How liver damage progresses
Liver disease usually follows a pattern. First, an injury begins—alcohol exposure, a viral infection, obesity, or an autoimmune attack on liver cells. The liver responds with inflammation as it tries to repair itself. If the injury stops, the inflammation goes away and the liver heals. If the injury continues, inflammation becomes chronic.
Chronic inflammation triggers the liver to form scar tissue as part of the healing process. This stage is called fibrosis. Fibrosis can progress slowly or quickly depending on the cause, your genetics, and whether you have other conditions like diabetes or hepatitis C. At this stage, the liver still works, but less efficiently.
If fibrosis worsens, it becomes cirrhosis. The scarring is now so extensive that the liver cannot function normally. Blood backs up in the vessels that feed the liver, causing fluid to leak into the belly and legs. The liver cannot make enough clotting proteins, so you bleed more easily. Toxins that the liver normally filters build up in your blood and brain. At this point, liver failure is a real risk.
Why symptoms often come late
The liver has no pain nerves, so liver disease does not hurt. Early fibrosis causes no symptoms at all. Many people with fatty liver disease or early hepatitis have no idea they are affected because they feel completely normal.
Symptoms usually appear only when cirrhosis develops or liver function drops significantly. Then you might notice fatigue, loss of appetite, nausea, yellowing of the skin and eyes (jaundice), swelling in the legs or belly, or dark urine. By the time these symptoms appear, substantial damage has already occurred.
This is why doctors screen for liver disease in people with risk factors—heavy alcohol use, obesity, diabetes, or known hepatitis infection—even when they have no symptoms. A blood test and sometimes an ultrasound can detect fibrosis before it becomes cirrhosis.
What causes liver disease
Alcohol is a common cause. Heavy drinking over years damages liver cells and triggers inflammation and scarring. The amount that causes damage varies by person, but sustained heavy use is the main risk factor.
Obesity and type 2 diabetes cause fatty liver disease. Fat accumulates in liver cells, and in some people this triggers inflammation and fibrosis. This form of liver disease is becoming more common as obesity rates rise.
Viral hepatitis—especially hepatitis B and C—can cause chronic infection that slowly damages the liver over decades. Hepatitis B spreads through blood and body fluids; hepatitis C spreads through blood contact. Many people with chronic hepatitis have no symptoms for years.
Autoimmune liver disease occurs when your immune system attacks liver cells. Autoimmune hepatitis, primary biliary cholangitis, and primary sclerosing cholangitis are rare but serious. Genetic conditions like hemochromatosis (too much iron) and Wilson disease (too much copper) also damage the liver if untreated. Other causes include certain medications, nonalcoholic fatty liver disease, and bile duct blockages.
How doctors diagnose liver disease
Diagnosis usually starts with blood tests. Liver function tests measure enzymes and proteins the liver makes. Elevated levels suggest the liver is inflamed or damaged. Tests for hepatitis antibodies and viral load show whether you have a hepatitis infection. A test called AST-to-platelet ratio index (APRI) uses two blood values to estimate whether you have fibrosis.
If blood tests suggest fibrosis, your doctor may order an ultrasound or a specialized ultrasound called transient elastography (FibroScan), which measures liver stiffness. Stiff liver tissue suggests scarring. A liver biopsy—taking a small sample of liver tissue with a needle—can show exactly how much scarring is present, but it is less common now because imaging and blood tests are often enough.
Screening is recommended for people with hepatitis B or C, heavy alcohol use, obesity, or diabetes. If you fall into one of these groups, talk to your doctor about whether testing makes sense for you.
Treatment depends on the cause
If you have hepatitis B, antiviral medications can suppress the virus and prevent further liver damage. Hepatitis C can now be cured with direct-acting antiviral drugs taken for 8 to 12 weeks. Hepatitis A does not require treatment—your immune system clears it on its own.
For fatty liver disease, there is no medication yet. Treatment focuses on the underlying cause: losing weight if you are overweight, controlling diabetes, and stopping alcohol if that is a factor. These changes can reduce fat in the liver and reverse early-stage disease.
For autoimmune liver disease, immunosuppressant medications reduce the immune attack. For cirrhosis, treatment aims to manage complications—diuretics for fluid buildup, medications to lower blood pressure in the liver, and screening for liver cancer. If cirrhosis is advanced, a liver transplant may be the only option.
Frequently Asked Questions
Can you have liver disease without any symptoms?
Yes. Fatty liver disease, early fibrosis, and chronic hepatitis often cause no symptoms at all. Many people discover they have liver disease only when they have blood work done for another reason or when a doctor screens them because of risk factors like obesity or hepatitis infection.
Is liver disease always permanent?
Not always. Early fatty liver disease can reverse if you lose weight or stop drinking. Hepatitis A clears on its own. Hepatitis C can be cured with medication. But once cirrhosis develops, the scarring cannot be undone, though treatment can slow progression and manage complications.
What is the difference between fibrosis and cirrhosis?
Fibrosis is early scarring of the liver. The liver still functions, though less efficiently. Cirrhosis is advanced scarring where so much scar tissue has formed that the liver cannot work normally. Fibrosis can progress to cirrhosis, but not everyone with fibrosis develops cirrhosis.
Can you live a normal life with liver disease?
This depends on the stage and type. Many people with early fibrosis or well-controlled hepatitis live normal lifespans with treatment and lifestyle changes. People with cirrhosis need ongoing medical care and may face complications, but treatment can extend life and improve quality of life.
How do I know if I should be screened for liver disease?
Talk to your doctor if you drink heavily, are overweight, have type 2 diabetes, or know you have been exposed to hepatitis. Your doctor can decide whether blood tests or imaging make sense based on your individual risk factors.