fatty liver disease

Overview
Fatty liver disease is a condition where excess fat builds up in the liver, interfering with its normal function. There are two main types: nonalcoholic fatty liver disease (NAFLD) and alcohol-associated fatty liver disease (AFLD). In its early stages, it may not cause any symptoms, but over time it can lead to inflammation, liver scarring (fibrosis), or cirrhosis. The liver is a vital organ involved in filtering toxins, storing energy, and helping digest food, so when it’s affected, many body systems can suffer.

Why It’s Important
Fatty liver disease is one of the leading causes of chronic liver disease in the world and is especially concerning because it often develops silently. If left untreated, it can progress to nonalcoholic steatohepatitis (NASH), cirrhosis, liver failure, or even liver cancer. It’s also closely tied to obesity, diabetes, and heart disease, making it a major public health issue. Detecting and addressing it early can prevent serious complications.

Quick Facts

  • Affects both children and adults, but most common in people over 40

  • NAFLD affects about 1 in 4 adults globally

  • Can be reversible with early intervention

  • NAFLD occurs in people who drink little to no alcohol

  • Two main types: Simple fatty liver (steatosis) and NASH (involves liver inflammation and damage)

  • Often goes undiagnosed due to lack of early symptoms

What Happens in the Body
Fat begins to accumulate in liver cells when the body produces too much fat or doesn’t metabolize it efficiently. In NAFLD, this buildup is unrelated to alcohol and is usually linked to insulin resistance, obesity, and metabolic syndrome. If inflammation occurs (NASH), it can cause liver cell damage and trigger fibrosis (scarring), which may progress to cirrhosis, a condition where normal liver tissue is replaced by scar tissue, impairing liver function.

Common Signs and Symptoms
Most people have no symptoms in the early stages. When present, symptoms may include:

  • Fatigue

  • Upper right abdominal discomfort

  • Unexplained weight loss

  • Enlarged liver (hepatomegaly)

  • Jaundice, swelling, or confusion (in advanced disease)

Diagnosis

  • Blood tests (elevated liver enzymes like ALT and AST)

  • Imaging tests such as ultrasound, CT scan, or MRI

  • FibroScan® to assess liver stiffness (fibrosis)

  • Liver biopsy is the gold standard to confirm NASH or advanced fibrosis
    See a doctor if:

  • You have risk factors (obesity, diabetes, high cholesterol)

  • Liver enzymes are elevated on routine labs

  • You have persistent fatigue or abdominal discomfort

Treatment and Management

  • Weight loss is the most effective treatment (aim for 5–10% body weight reduction)

  • Healthy diet (Mediterranean-style, low sugar and saturated fat)

  • Regular physical activity (aerobic + resistance training)

  • Manage diabetes, high cholesterol, and blood pressure

  • Limit or avoid alcohol

  • Vitamin E or pioglitazone may be considered in some NAFLD cases (under medical supervision)

  • No FDA-approved medication yet specifically for NAFLD/NASH

  • Liver transplant may be needed in cases of end-stage liver disease

Risks and Complications

  • Progression to NASH (inflammatory form)

  • Fibrosis and cirrhosis

  • Liver cancer (hepatocellular carcinoma)

  • Liver failure

  • Increased risk of heart disease, kidney disease, and type 2 diabetes

Who Is at Risk

  • Overweight or obese individuals

  • People with type 2 diabetes or insulin resistance

  • Those with high cholesterol or triglycerides

  • Postmenopausal women

  • People with polycystic ovary syndrome (PCOS)

  • People with sedentary lifestyles and unhealthy diets

Related Conditions

  • Type 2 diabetes

  • Metabolic syndrome

  • Obesity

  • Cardiovascular disease

  • Chronic kidney disease

When to See a Doctor

  • If you have risk factors and haven’t had your liver enzymes checked

  • If you’re experiencing persistent fatigue, abdominal pain, or jaundice

  • If you’ve been diagnosed and need guidance for lifestyle changes or referrals to a specialist

Last Updated: June 28, 2025