Drinking too much alcohol can cause a buildup of fat in your liver. That can lead to scarring of liver tissue, known as cirrhosis. The more scarred a liver is, the less well it functions. But fatty tissue can also build up in your liver if you drink little or no alcohol. This is known as nonalcoholic fatty liver disease (NAFLD). It can also cause cirrhosis.

Lifestyle changes can often help keep NAFLD from getting worse. But for some people, the condition can lead to life-threatening liver problems.

NAFLD and alcoholic liver disease (ALD) fall under the umbrella term of fatty liver disease. When 5 to 10 percent of a liver’s weight is made of fat, the condition can be defined as hepatic steatosis.

In many cases of NAFLD, there are no noticeable symptoms. When signs are present, they usually include:

  • pain in the upper right side of the abdomen
  • fatigue
  • an enlarged liver or spleen (usually observed by a doctor during an exam)
  • ascites, or swelling in your belly
  • jaundice, or yellowing of your skin and eyes

If NAFLD progresses to cirrhosis, symptoms may include:

  • mental confusion
  • internal bleeding
  • fluid retention
  • loss of healthy liver function

The exact causes of NAFLD aren’t well understood. There appears to be a connection between the disease and insulin resistance.

Insulin is a hormone. When your muscles and tissue need glucose (sugar) for energy, insulin helps unlock cells to take in glucose from your blood. Insulin also helps the liver store excess glucose.

When your body develops insulin resistance, it means your cells don’t respond to insulin the way they should. As a result, an excessive amount of fat ends up in the liver. This can lead to inflammation and liver scarring.

NAFLD affects an estimated 20 percent of the population. Insulin resistance appears to be the strongest risk factor, though you can have NAFLD without being insulin resistant.

People who are most likely to develop insulin resistance include people who are overweight or lead a sedentary lifestyle.

Other risk factors for NAFLD include:

  • diabetes
  • high cholesterol levels
  • high triglyceride levels
  • use of corticosteroids
  • use of certain medications for cancer, including Tamoxifen for breast cancer
  • pregnancy

Poor eating habits or sudden weight loss may also raise your risk of NAFLD.

NAFLD usually has no symptoms. So diagnosing the problem often starts after a blood test finds higher-than-normal levels of liver enzymes. A standard blood test could reveal these results.

High levels of liver enzymes could also suggest other liver diseases. Your doctor will need to rule out other conditions before diagnosing NAFLD.

An ultrasound of the liver can help reveal excessive fat content in the liver. Another type of ultrasound, called transient elastography, measures your liver’s stiffness. Greater stiffness suggests greater scarring.

If these tests are inconclusive, your doctor may recommend a liver biopsy. In this test, the doctor removes a small sample of liver tissue with a needle inserted through your abdomen. The sample is studied in a lab for signs of inflammation and scarring.

If you have symptoms such as right-side abdominal pain, jaundice, or swelling, don’t hesitate to see a doctor.

The main risk of NAFLD is cirrhosis, which can limit your liver’s ability to do its job. Your liver has several important functions, including:

  • producing bile, which helps break down fats and remove waste products from the body
  • metabolizing medication and toxins
  • balancing fluid levels in the body through protein production
  • processing hemoglobin and storing iron
  • converting ammonia in your blood to harmless urea for excretion
  • storing and releasing glucose (sugar) as needed for energy
  • producing cholesterol, which is necessary for cellular health
  • removing bacteria from blood
  • producing immune factors to fight infections
  • regulating blood clotting

Cirrhosis can sometimes progress to liver cancer or liver failure. In some cases, liver failure can be treated with medications, but usually a liver transplant is needed.

Mild cases of NAFLD may not lead to serious liver problems or other complications. For mild cases, early diagnosis and lifestyle changes are vital to preserving liver health.

There is no specific medication or procedure to treat NAFLD. Instead, your doctor will recommend several important lifestyle changes. These include:

  • losing weight if you’re obese or overweight
  • eating a diet made of mostly fruits, vegetables, and whole grains
  • exercising at least 30 minutes daily
  • controlling your cholesterol and blood glucose levels
  • avoiding alcohol

It’s also important to follow up on doctor appointments and to report any new symptoms as they develop.

If you can make the recommended lifestyle changes early on, you may be able to preserve good liver health for a long time. You may even be able to reverse liver damage in the earliest stages of the disease.

Even if you don’t feel any symptoms from NAFLD, that doesn’t mean liver scarring isn’t already occurring. To reduce your risk, follow a healthy lifestyle and have regular blood work done, including liver enzyme tests.