What causes cirrhosis

Overview

Cirrhosis is a late stage of scarring (fibrosis) of the liver caused by many forms of liver diseases and conditions, such as hepatitis and chronic alcoholism. Each time your liver is injured — whether by a virus, too much alcohol, or another disease — it tries to repair itself. In the process, scar tissue forms. As cirrhosis progresses, scar tissue replaces healthy liver tissue, blocking blood flow through the liver and preventing it from working properly. Ultimately, this can lead to liver failure.

What are the main causes of cirrhosis?

The development of cirrhosis is typically a consequence of prolonged and repeated liver injury. The body's natural healing process, which involves inflammation and the formation of scar tissue, becomes overactive and disorganized over time. When this scar tissue accumulation becomes widespread and severe, it disrupts the normal structure and function of the liver. Several conditions can lead to this chronic liver damage:

1. Chronic Viral Hepatitis

Infections with the hepatitis B virus (HBV) and hepatitis C virus (HCV) are among the most common causes of cirrhosis worldwide. These viruses directly attack liver cells, causing inflammation and damage that, over years or decades, can lead to extensive scarring. Hepatitis B is more prevalent in parts of Asia and Africa, while hepatitis C has a significant global impact. Without treatment, chronic hepatitis infections can progress silently, with symptoms often not appearing until the liver is already significantly damaged.

2. Alcoholic Liver Disease

Excessive and prolonged alcohol consumption is a major cause of cirrhosis, especially in Western countries. Alcohol is toxic to liver cells, causing inflammation (alcoholic hepatitis) and oxidative stress. The liver attempts to metabolize alcohol, but this process generates harmful byproducts that damage liver tissue. Binge drinking can also contribute, but it's the cumulative effect of heavy drinking over many years that most often leads to cirrhosis. The amount of alcohol that causes cirrhosis varies among individuals, but generally, heavy drinking over 10-15 years is considered a significant risk factor.

3. Non-Alcoholic Fatty Liver Disease (NAFLD)

NAFLD is a spectrum of liver conditions characterized by the buildup of excess fat in the liver, not caused by heavy alcohol use. It is strongly associated with obesity, type 2 diabetes, high cholesterol, and metabolic syndrome. In its more severe form, non-alcoholic steatohepatitis (NASH), there is inflammation and liver cell damage, which can progress to fibrosis and eventually cirrhosis. As rates of obesity and diabetes rise globally, NAFLD is becoming an increasingly important cause of cirrhosis and liver transplantation.

4. Autoimmune Hepatitis

In autoimmune hepatitis, the body's own immune system mistakenly attacks and damages liver cells. This chronic inflammation can lead to progressive scarring and cirrhosis. It's more common in women and often requires long-term management with immunosuppressive medications.

5. Genetic and Inherited Conditions

Certain genetic disorders can lead to the accumulation of harmful substances in the liver, causing damage and cirrhosis. Key examples include:

• Hemochromatosis: This condition causes the body to absorb too much iron from the diet, leading to iron overload in organs, including the liver. Excess iron can damage liver cells and cause scarring.
• Wilson's Disease: In this rare inherited disorder, copper builds up in the liver, brain, and other organs. The excess copper is toxic to the liver, leading to inflammation and cirrhosis.
• Alpha-1 Antitrypsin Deficiency: This genetic disorder can affect the lungs and liver. In the liver, it can lead to the buildup of abnormal proteins, causing inflammation and cirrhosis.

6. Bile Duct Diseases

Conditions that obstruct or damage the bile ducts, which carry bile from the liver to the small intestine, can cause cirrhosis. Bile backup can lead to liver inflammation and scarring. Examples include primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC).

7. Other Causes

Less common causes of cirrhosis include:

• Certain Medications: Long-term use of some drugs can cause liver damage.
• Parasitic Infections: Certain parasites, like those causing schistosomiasis, can damage the liver.
• Heart Failure: Severe, long-standing right-sided heart failure can lead to congestion in the liver, causing "cardiac cirrhosis."
• Cystic Fibrosis: While primarily affecting the lungs and pancreas, cystic fibrosis can also lead to liver disease and cirrhosis in some individuals.

It's important to note that sometimes the cause of cirrhosis cannot be identified, a condition known as cryptogenic cirrhosis. Early detection and management of underlying liver conditions are crucial to prevent or slow the progression of cirrhosis.