What is fatty liver, and how worried should you be?

“Fatty liver” is written on your ultrasound report

Most people who hear this phrase had an ultrasound or blood test for another reason. The NHS also says fatty liver is often found during tests or imaging done for something else. The first reaction is usually fear: “Is my liver damaged?” The short answer is that most people with fatty liver do not develop serious problems, but it should not be ignored.

What does fatty liver mean?

It means more fat than normal has collected in the liver. NIDDK says one of the causes is non-alcoholic fatty liver disease, which is now also called MASLD. The simple type has fat only. The other type, NASH (newly named MASH), has inflammation as well as fat and can lead to hardening of the liver, called cirrhosis. NIDDK says weight can move a person between these two states, which means there is a way back.

The NHS describes the stages in a similar way: most people are in the first stage, which is just fat and usually causes no trouble. Only a small number progress to the stages of inflammation, scarring and cirrhosis, and lifestyle can stop that progression.

Does it cause symptoms?

Usually not. NIDDK calls it a “silent” disease. If there are symptoms, they are tiredness or discomfort in the upper right of the abdomen. The NHS says the same and adds that you may feel generally unwell. So having no symptoms does not mean no check is needed, and it does not mean the liver is healthy.

Why does it appear?

NIDDK says the causes are still being studied. Genes, medical conditions and diet all play a part. Known risk factors:

• Overweight or obesity, especially around the waist
• Insulin resistance or type 2 diabetes
• High blood fats
• Metabolic syndrome (high blood pressure, blood sugar and blood fats together with a large waist)

Besides these, the NHS lists inactivity, an unhealthy diet, high blood pressure and being over fifty. NIDDK says some medicines, very rapid weight loss, malnutrition and alcohol can also raise liver fat. If you take any medicine, do not stop it without advice; just tell your doctor its name.

How is it checked?

NIDDK says the doctor usually asks about and looks at these things: weight, activity, sugar and sweet drinks, alcohol, and the risk factors above. Then:

• Blood tests. High liver enzymes (ALT and AST) make a doctor think of fatty liver. Routine test results can also be used to estimate scarring. Other tests are needed to rule out other causes. The NHS also mentions blood tests and sometimes an ultrasound.
• Imaging. Ultrasound, CT and MRI show fat, but they do not show inflammation or scarring.
• Elastography. A newer way to measure liver stiffness, which can give information about scarring.
• Liver biopsy. The only test that confirms inflammation for certain, and it is not needed for everyone. It is used only when advanced disease is possible or another cause is being considered.

Which of these you need is your doctor’s decision.

What does a high liver enzyme mean?

It means liver cells have been injured, but there is more than one possible cause. Fatty liver is a common cause, but NIDDK says the doctor orders more tests to rule out other causes. So do not read a high number with anxiety, and do not prescribe yourself medicines or supplements.

What is the treatment?

NIDDK and the NHS both see lifestyle change as the main treatment:

• Weight loss, slowly. According to NIDDK, shedding 3 to 5 percent of your weight is enough to lower liver fat, while improving inflammation and scarring can take 7 to 10 percent. Losing weight fast makes the disease worse.
• Activity. Regular exercise helps the liver even without weight loss. The NHS suggests at least one hundred and fifty minutes of activity a week.
• Food. A balanced diet and smaller meals. See the food guide.
• Alcohol and smoking. The NHS recommends keeping alcohol low and quitting smoking. If you are concerned about alcohol, be honest with your doctor; they ask in order to help, not to judge.

About medicines: lifestyle change is still the main treatment. For the inflammatory type with moderate or advanced fibrosis, the US Food and Drug Administration has conditionally approved medicines since 2024. Whether these are needed for you, and available in Iran, is for a specialist to say. The NHS says that in cases of scarring a specialist may prescribe medicine, and that there are other options for severe obesity. Both sources make clear that these are the doctor’s decisions. Do not take herbal remedies or supplements without asking either, because NIDDK warns that some are harmful to the liver.

Follow-up

The NHS says an annual review and periodic checks are usually needed. Your doctor sets the follow-up interval based on the condition of your liver.

When to see a doctor sooner

If you have yellow eyes or skin, dark urine, fever with severe upper abdominal pain, vomiting blood or black tarry stool, a swollen abdomen, or confusion, do not wait for an appointment. Read urgent warning signs and call 115 (Iran’s emergency number).

Summary

• Fatty liver is common and most of the time silent.
• Not every fatty liver has inflammation; the doctor decides with tests and imaging.
• Slow weight loss and regular activity are the most effective step.
• Medicines and supplements only on a doctor’s advice.
• Do not put off yellow skin or eyes, fever with severe pain, or vomiting blood until tomorrow.