Fatty liver, or hepatic steatosis, is a term that describes the buildup of fat in the liver. It’s normal to have small amounts of fat in your liver, but too much can become a health problem.
The liver is the second largest organ in the body. It’s responsible for a wide variety of functions, including processing everything we eat and drink, and filtering harmful substances from the blood. Too much fat in the liver can lead to long-term liver damage.
Early stage fatty liver is diagnosed when the proportion of liver cells that contain fat is more than 5 percent. This is often diagnosed by looking at small samples taken from the liver under the microscope. Ultrasounds, CT scans, and MRI scans can also help evaluate the fat content of the liver.
The liver commonly repairs itself by rebuilding new liver cells when the old ones are damaged. When there’s repeated damage to the liver, permanent scarring takes place. This condition is called cirrhosis. In mild forms, fatty liver can be a reversible condition that may improve with lifestyle modifications such as diet changes, weight loss, and increased physical activity. In many cases, fatty liver has no symptoms.
Fatty liver becomes harmful to the liver when it progresses. Liver inflammation (steatohepatitis) can lead to liver scarring, liver cancer, and end-stage liver disease.
Fatty liver typically has no associated symptoms. However, research has shown that about 20 percent of people with fatty liver inflammation progress to worse conditions. If this occurs you may experience fatigue or abdominal discomfort. Your liver may become slightly enlarged, which your doctor may be able to detect during a physical exam.
It’s believed that the excess fat in the liver, along with certain medical conditions, increases inflammation. If your liver becomes inflamed, you may have symptoms such as:
- a poor appetite
- weight loss
- abdominal pain
- physical weakness
If fatty liver progresses to cirrhosis and liver failure, symptoms can include:
- an enlarging, fluid-filled abdomen
- jaundice of the skin and eyes
- abnormal bleeding
The most common cause of fatty liver is alcohol use disorder and heavy drinking. In many cases, it’s much less clear what causes fatty liver in people who don’t drink much alcohol. However, higher body weight, a high processed sugar diet, high triglycerides, diabetes, low physical activity, and genetics all play a role.
Fatty liver develops when the body creates too much fat or cannot metabolize fat efficiently enough. The excess fat is stored in liver cells where it accumulates and causes fatty liver disease.
Besides alcohol use disorder, other common causes of fatty liver include:
- hyperlipidemia, or high levels of fats in the blood, especially high triglycerides
- genetic inheritance
- rapid weight loss
- side effects of certain medications, including methotrexate (Trexall), tamoxifen (Nolvadex), amiodorone (Pacerone), and valproic acid (Depakote)
If your liver is inflamed, your doctor may be able to detect it by examining your abdomen for an enlarged liver. However, your liver can be inflamed without being enlarged. Let your doctor know if you’ve been experiencing fatigue or loss of appetite. Also, tell your doctor about any history of alcohol, medication, and supplement use.
Your doctor may find that liver enzymes are higher than normal during a routine blood test. This doesn’t confirm a diagnosis of fatty liver, but it does relate to liver inflammation. Further analysis is necessary to find the cause of the inflammation.
Your doctor may use an ultrasound to detect fat in your liver. Other imaging studies may also be done, such as CT or MRI scans.
Another imaging test similar to ultrasound is a FibroScan. Like an ultrasound, a FibroScan utilizes sound waves to determine the density of the liver and the corresponding areas of fat and normal liver tissue.
Imaging studies can detect fat in the liver, but they cannot help your doctor confirm the extent of damage.
A liver biopsy is still considered the best way to determine the severity of liver disease. During a liver biopsy, your doctor will insert a needle into the liver and remove a piece of tissue for examination. They will give you a local anesthetic to lessen the pain.
A liver biopsy is the only way to know for certain the severity of fatty liver or other liver diseases. The biopsy can also help your doctor determine the exact cause.
Research is ongoing into medications that may help treat fatty liver. The first-line of treatment continues to be following recommendations to reduce your risk factors. These recommendations typically include:
- limiting or avoiding alcoholic beverages
- managing your cholesterol and reducing your intake of sugars and saturated fats
- losing weight
- controlling your blood sugar
If you have fatty liver because of obesity or unhealthy eating habits, your doctor may also suggest that you increase physical activity and eliminate or add certain types of foods to your diet. Reducing the number of calories you eat each day can help you lose weight and heal your liver.
In the early stages, you can improve and reverse fatty liver disease by reducing or eliminating fatty foods and foods high in sugar from your diet. Choose a balanced diet with healthier foods such as fresh fruits, fresh vegetables, whole grains, and healthy fats like those in nuts and avocados. Replace red meats with lean proteins such as soy, chicken, turkey, and fish. Sweetened drinks, juices, and sodas should be avoided.
Most cases of fatty liver don’t progress into other forms of liver disease. The liver can repair itself, so if you take the necessary steps to treat high cholesterol, diabetes, an unhealthy diet, and obesity, you can reverse fatty liver.
If you’re a heavy drinker, stop drinking alcohol or limit your intake to 1 drink or less per day for women and 2 drinks or less per day for men. A liver biopsy can help your doctor identify permanent liver damage, and determine the severity of damage.
If fatty liver persists and is not reversed, it can progress into liver disease, cirrhosis, or cancer. The progression to cirrhosis is dependent on the cause. In alcoholic fatty liver, continuing to drink alcohol in excess can lead to liver failure.
The progression of nonalcoholic fatty liver disease varies, but in most people it does not lead to liver scarring and cirrhosis. However, if you’re diagnosed with steatohepatitis, you have a higher chance of developing scarring and liver disease. Twenty percent of people with steatohepatitis will go on to develop worsening liver disease.
If fatty liver progresses to cirrhosis, the risk of liver failure and death rises significantly. There is also a higher risk for liver cancer and death from heart disease.
Protecting your liver is one of the best ways to prevent fatty liver and its complications. You can start by taking several steps:
- limit or eliminate alcohol from your diet
- eat a healthy, balanced diet
- control diabetes if you have developed the condition
- aim for at least 30 minutes of exercise most days of the week
By taking these steps, you’ll not only keep your liver healthy but also improve your overall health.