How the liver works and what goes wrong

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 cells become damaged or scarred, they cannot do these jobs well. The damage can happen slowly over years or quickly over weeks, depending on the cause.

Liver disease develops when something injures the liver cells faster than the body can repair them. The most common causes are chronic hepatitis B or C infection, heavy alcohol use over many years, obesity, and autoimmune conditions where your immune system attacks liver cells. Less common causes include inherited genetic disorders, certain medications, and bile duct blockages. Some people have no known cause—doctors call this idiopathic liver disease.

As damage builds up, scar tissue replaces healthy liver tissue in a process called fibrosis. If fibrosis continues, it becomes cirrhosis, where the liver becomes so scarred it cannot function. Cirrhosis is permanent and can lead to liver failure, where the liver stops working altogether.

Key Takeaways

  • Liver disease develops when cells are damaged faster than they can heal, most commonly from hepatitis infection, alcohol use, or obesity.
  • Early-stage liver disease often has no symptoms, so blood tests are the main way doctors find it before serious damage occurs.
  • Treatment depends on the cause: antiviral drugs for hepatitis, stopping alcohol use, weight loss for fatty liver disease, and immunosuppressants for autoimmune conditions.
  • Cirrhosis cannot be reversed, but slowing its progress can prevent liver failure and the need for transplant.
  • A liver transplant is the only cure for end-stage liver disease, but organs are scarce and transplant requires lifelong medication.

How doctors diagnose liver disease

Doctors usually discover liver disease through blood tests that measure liver enzymes and proteins. Two key tests are ALT and AST, enzymes that leak into the blood when liver cells are damaged. Another is bilirubin, a yellow pigment the liver normally processes—high levels cause jaundice, the yellowing of skin and eyes. A test called INR measures how well your liver makes clotting proteins.

If blood tests suggest liver damage, your doctor may order an ultrasound or CT scan to look at the liver's size and texture. A fibroscan (transient elastography) uses sound waves to measure how much scar tissue is present without a needle. If the diagnosis is still unclear, a liver biopsy—removing a tiny sample of tissue with a needle—can show exactly what type of damage is present and how advanced it is.

The stage of liver disease matters for treatment decisions. Doctors use a system called the Child-Pugh score or MELD score (Model for End-Stage Liver Disease) to measure how much liver function remains. These scores help predict outcomes and determine whether someone needs a transplant soon.

Treatment depends on what caused the damage

If you have chronic hepatitis B, antiviral medications can slow or stop the virus from damaging more liver cells. These drugs do not cure hepatitis B, but they reduce the viral load enough that your immune system can control it. Hepatitis C is different—newer antiviral drugs called direct-acting antivirals can actually cure it in 8 to 12 weeks, even in people with cirrhosis.

For alcoholic liver disease, stopping alcohol use is the most important treatment. If you continue drinking, the damage will progress no matter what medication you take. Doctors can refer you to addiction specialists or support programs. Some people benefit from medications like naltrexone or acamprosate that reduce cravings.

For nonalcoholic fatty liver disease (NAFLD), weight loss of 5 to 10 percent of body weight can reduce fat in the liver and inflammation. There is no FDA-approved medication yet, though several are in clinical trials. Managing diabetes and high cholesterol also helps slow progression.

For autoimmune hepatitis, corticosteroids and immunosuppressant drugs reduce the immune attack on liver cells. For primary biliary cholangitis and primary sclerosing cholangitis, ursodeoxycholic acid slows bile duct damage. These conditions require ongoing treatment to prevent cirrhosis.

What happens when cirrhosis develops

Once cirrhosis forms, the scarring is permanent. The goal of treatment shifts from reversing damage to slowing its progress and managing complications. Cirrhosis causes blood to back up in the portal vein, the vessel that carries blood to the liver. This backup creates high pressure called portal hypertension.

Portal hypertension leads to several serious complications. Varices—enlarged veins in the esophagus or stomach—can rupture and cause life-threatening bleeding. Fluid builds up in the abdomen (ascites) and legs (edema). The liver cannot clear ammonia from the blood, which builds up and damages the brain, causing confusion and memory problems (hepatic encephalopathy). The kidneys can fail (hepatorenal syndrome). Doctors treat these with medications, dietary changes, and procedures like banding varices to prevent bleeding.

People with cirrhosis also have a higher risk of liver cancer. Screening with ultrasound and blood tests for alpha-fetoprotein (AFP) every 6 months can catch cancer early, when treatment is more effective.

Liver transplant: when and how it works

A liver transplant is the only cure for end-stage liver disease. You may be considered for transplant if your liver is failing and you have tried all other treatments. Doctors use the MELD score to prioritize patients—those with the lowest liver function get organs first.

The surgery removes your diseased liver and replaces it with a healthy one from a donor who has died (deceased donor) or from a living donor, usually a family member or friend. Living donor transplants have better outcomes because surgery happens sooner and the organ is healthier, but they carry risk for the donor.

After transplant, you must take immunosuppressant medications for life to prevent your immune system from rejecting the new liver. These drugs have side effects and require regular blood tests to monitor levels. Even with a transplant, some diseases like hepatitis C can return in the new liver, though newer antiviral drugs can treat it.

The shortage of donor organs means many people die waiting for a transplant. In the United States, about 2,000 people receive liver transplants each year, but roughly 10,000 are on the waiting list.

Lifestyle changes that slow progression

No matter what type of liver disease you have, certain habits reduce further damage. Stop drinking alcohol completely—even small amounts can harm a cirrhotic liver. Eat a balanced diet low in salt to help manage fluid buildup. Avoid raw shellfish, which can carry bacteria that cause serious infections in people with cirrhosis.

Get vaccinated against hepatitis A and B if you are not immune, and against influenza and pneumococcal disease. These infections are more dangerous when your liver is weak. If you have hepatitis B or C, tell your sexual partners and household contacts so they can be tested and vaccinated if needed.

Limit acetaminophen (Tylenol) to no more than 2,000 mg per day, and avoid NSAIDs like ibuprofen if possible—both can damage a weakened liver. Talk to your doctor before starting any new medication or supplement, because the liver processes most drugs and a damaged liver may not clear them safely.

Monitoring and follow-up care

Once you are diagnosed with liver disease, regular follow-up is essential. Your doctor will order blood tests every 3 to 6 months to track liver function and watch for complications. If you have cirrhosis, you will need ultrasound screening for liver cancer every 6 months. You may see a hepatologist (liver specialist) rather than a general doctor, especially if your disease is advanced.

Keep a record of your test results and bring them to each appointment. This helps you and your doctor spot trends—whether your liver function is stable, improving, or declining. If your condition worsens, your doctor can discuss transplant options earlier, when you are healthier and more likely to survive surgery.

Frequently Asked Questions

Can you live a normal life with liver disease?

Early-stage liver disease often causes no symptoms, and many people live decades without knowing they have it. With treatment of the underlying cause—like curing hepatitis C or stopping alcohol—you can prevent progression. Once cirrhosis develops, life expectancy depends on how well you manage complications, but many people live years with careful monitoring and treatment.

Is liver disease always inherited?

Most liver disease is not inherited. The common causes—hepatitis infection, alcohol use, and obesity—are acquired during life. Some types are inherited, like hemochromatosis (too much iron storage) and alpha-1 antitrypsin deficiency, but these are rare. A family history of liver disease may mean you share risk factors like hepatitis exposure, not necessarily genes.

Can you reverse liver damage?

Early fibrosis can sometimes improve if you remove the cause—stopping alcohol, curing hepatitis C, or losing weight can reduce scarring. Once cirrhosis forms, the scarring is permanent and cannot be reversed. However, stopping the cause can slow further damage and prevent complications.

What is the difference between hepatitis and liver disease?

Hepatitis is inflammation of the liver, usually caused by viral infection (hepatitis A, B, C, D, or E), alcohol, or autoimmune attack. Liver disease is a broader term that includes hepatitis but also fatty liver disease, cirrhosis, genetic disorders, and any condition that damages liver function. You can have hepatitis without cirrhosis, or cirrhosis from a cause other than hepatitis.

Do I need to change my diet if I have liver disease?

Diet matters most if you have cirrhosis. Limit salt to reduce fluid buildup, eat enough protein to maintain muscle (unless you have hepatic encephalopathy, when protein must be restricted), and avoid alcohol completely. If you are overweight, gradual weight loss helps, especially for fatty liver disease. Your doctor or a dietitian can create a plan tailored to your stage of disease.