Fatty Liver Disease Causes, Symptoms and Treatment

Fatty liver disease is one of the most common liver conditions in the United States, affecting millions of adults. While often silent in its early stages, fatty liver disease can progress to serious complications if left untreated. 

Froedtert & MCW hepatologists provide expert care for fatty liver problems. With early detection, lifestyle changes and advanced treatment options, we can prevent or even reverse fatty liver disease. 

What is Fatty Liver Disease?

Fatty liver disease, also known as hepatic steatosis or steatotic liver disease (SLD), occurs when excess fat builds up in the liver. While a small amount of fat is normal, when fat makes up more than 5% of the liver, it can impair liver function and lead to serious complications such as fibrosis, cirrhosis or liver cancer. 

There are two main types: 

• Alcohol-related fatty liver disease (AFLD): Excessive alcohol intake damages liver cells over time. 

• Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD): Formerly called nonalcoholic fatty liver disease (NAFLD), MASLD is fat buildup not related to significant alcohol use, often linked to obesity, diabetes, high cholesterol or metabolic syndrome.

Causes and Risk Factors

Fatty liver disease develops when the liver is unable to properly break down and process fats. Common risk factors include: 

• Obesity or overweight 
• Type 2 diabetes or insulin resistance 
• High blood pressure and high cholesterol 
• Alcohol use 
• Certain medications or toxins 
• Genetic predisposition

Fatty Liver Disease Symptoms 

Fatty liver disease often has no early symptoms, which makes regular screening important. When symptoms do appear, they may include: 

• Fatigue and weakness 
• Discomfort or pain in the upper right abdomen 
• Loss of appetite or unexplained weight loss 
• Nausea 
• Jaundice (yellowing of skin and eyes) 
• Swelling in the abdomen or legs (ascites/edema)

Diagnosing Fatty Liver Disease 

• Doctors may use several methods to diagnose fatty liver: 
• Blood tests: Elevated liver enzymes (ALT, AST) may indicate liver injury. 
• Imaging: Ultrasound, CT scan, MRI or other scans measure fat and scarring. 
• Liver biopsy: A tissue sample may be taken to confirm inflammation or fibrosis

Treatment and Prevention

There is no single medication for fatty liver disease. Treatment focuses on managing risk factors and protecting liver health.

• Weight loss: Losing 7 to 10% of your body weight can significantly reduce liver fat. 
• Healthy diet: Emphasize fruits, vegetables, whole grains and lean proteins. Limit sugar, processed foods and saturated fats. 
• Exercise: Aim for at least 150 minutes of moderate activity per week. 
• Medications: Antidiabetic drugs (GLP-1 agonists, thiazolidinediones), vitamin E and other new therapies can be prescribed for advanced cases. 
• Avoid alcohol: Even small amounts can worsen liver damage. 
• Manage underlying conditions: Control diabetes, cholesterol and blood pressure. 
• Vaccinations for hepatitis A and B can prevent further liver damage.

When to See a Doctor

If you think you may have fatty liver disease, it’s important to contact a health care professional — especially if you notice symptoms such as: 

• Fatigue
• Malaise
• Discomfort in the upper right abdomen, which can occur in some cases of NAFLD/MASLD

You should also seek care promptly if you develop warning signs of more advanced liver involvement, including:

• Abdominal swelling (ascites)
• Leg swelling
• Jaundice
• Itchy skin
• Spider‑like blood vessels near the skin surface

Even if you don’t have symptoms, abnormal liver enzyme results on routine bloodwork or imaging findings suggesting excess liver fat are reasons to schedule an evaluation, as MASLD is often discovered incidentally.

In many health networks, including Froedtert & MCW, patients may need a referral from their primary care provider to see a hepatologist. This helps ensure appropriate testing is completed beforehand and allows specialists to efficiently assess liver health, rule out other causes and recommend treatment or lifestyle strategies to prevent disease progression. Early evaluation is especially important if you have risk factors such as obesity, insulin resistance, type 2 diabetes or elevated triglycerides, since these conditions significantly increase the likelihood of developing or worsening fatty liver disease.

Why Early Detection Matters 

When fatty liver disease is detected early, lifestyle changes can often reverse fat buildup and prevent progression. If left untreated, it may lead to cirrhosis, liver cancer or end-stage liver disease. Our liver specialists provide comprehensive evaluation and treatment for fatty liver disease, from early diagnosis to advanced care.