Nonalcoholic steatohepatitis, or NASH, is a chronic and potentially life-threatening liver disease that occurs in people who drink little or no alcohol.

What Is Nonalcoholic Steatohepatitis?

NASH is a severe form of nonalcoholic fatty liver disease, or NAFLD, that can cause significant, permanent damage to the liver. In NAFLD, excess fat is stored in the liver. NASH occurs when a fatty liver becomes inflamed and swollen. At this point, scar tissue begins to form in the liver called fibrosis. Over time, scar tissue accumulates and replaces healthy liver tissue, a process called cirrhosis that impairs liver function. Eventually, NASH can lead to liver failure and other serious health problems including cardiovascular disease, Type 2 diabetes and metabolic syndrome.

Causes of Nonalcoholic Steatohepatitis

The exact causes of NASH are not clear. Some cases may be caused by genetic health conditions, medications, infections or toxins. While NASH can develop in anyone at any age, it is more likely to occur in people middle-aged people or older who are overweight or obese. Additional factors that may contribute to NASH include:

• high blood levels of cholesterol and triglycerides, types of fat also called lipids
• high blood sugar from either prediabetes or Type 2 diabetes
• insulin resistance
• metabolic disorders such as metabolic syndrome
• oxidative stress, a deterioration inside liver cells
• release of inflammation-causing proteins by fat cells

Signs and Symptoms of Nonalcoholic Steatohepatitis

NASH usually does not cause symptoms in the early stages. As the condition progresses, NASH can cause symptoms of cirrhosis and liver failure such as:

• abdominal pain
• easy bleeding and bruising
• enlarged spleen
• fatigue
• fluid accumulation in the abdomen
• hepatic encephalopathy, a buildup of toxins in the blood that travels to the brain causing slurred speech, confusion and memory problems
• internal bleeding due to enlarged or swollen abdominal veins
• itchy skin
• jaundice, a yellowing of the skin and eyes
• spider veins, those small, twisted blood vessels visible just below the skin’s surface

In addition, NASH-related cirrhosis increases the risk of developing a liver cancer called hepatocellular carcinoma.

How Is Nonalcoholic Steatohepatitis Diagnosed?

Because NASH does not initially cause symptoms, it is often first detected during a routine blood test. If NASH is suspected, additional diagnostic tests may include:

• blood tests to rule out other possible causes of liver damage
• liver function tests to measure levels of substances made or metabolized in the liver
• imaging studies such as computerized tomography (CT) scans, magnetic resonance imaging (MRI) or ultrasound to detect fat in the liver
• liver biopsy to confirm a diagnosis of NASH as well as determine the severity of inflammation and scarring

Treatments for Nonalcoholic Steatohepatitis

Currently, there are no medications or other specific therapies that can reverse NASH. Treatment focuses on lifestyle changes to reduce body fat, lower levels of liver enzymes and minimize liver inflammation, including:

• avoiding alcohol
• eating a healthy diet with plenty of fruits, vegetables and whole grains, and limited amounts of red meat, salt, sugar and saturated fats
• getting more physical activity
• losing weight and maintaining weight loss

Some medications may have the potential to make NASH worse, especially in large doses. Ask your doctor if it is safe to take vitamins, dietary supplements, prescription drugs or over-the-counter medications, especially acetaminophen and non-steroidal anti-inflammatory drugs, or NSAIDs, such as ibuprofen and naproxen sodium.