What Causes Liver Disease?
If your doctor has raised concerns about your liver function or fat in your liver, you're likely wondering what it means for your overall health.
"The liver is one of the most important organs in the body," says Dr. David Victor, a liver specialist at Houston Methodist. "It's the recycling center, removing the waste created as the body functions, and it performs other critical roles."
The liver helps detoxify the body, breaking down harmful substances and medications. It produces bile, which aids digestion, and it's where many nutrients the body needs are created, processed and stored. With all of these important roles, it's no wonder that your liver needs to be functioning at its best.
"The earlier an issue with the liver is identified and addressed, the better," says Dr. Victor. "And liver health is something people need to be aware of because, unlike a sprained ankle, the liver doesn't hurt when something is wrong with it."
The true scope of liver disease can be somewhat hard to define, but, ultimately, it's when the liver becomes damaged for one reason or another.
"It starts with inflammation," says Dr. Victor. "Over time, this can progress into fibrosis and ultimately cirrhosis, which is permanent liver damage."
Some of this damage — inflammation and fibrosis — is reversible.
"The liver is the only organ that can regrow," explains Dr. Victor. "So, if there's not yet any permanent damage, the liver can heal itself and return to a normal state — so long as the cause of the damage is addressed."
Cirrhosis, when irreversible scarring develops in the liver, keeps the organ from working as it should. The more damage, the less effective the liver becomes at performing its important tasks.
"If the disease is allowed to progress, the liver can start to fail," says Dr. Victor. "At this point, a liver transplant is needed."
What leads to the liver becoming inflamed and damaged in the first place?
Liver disease can be caused by a variety of things, including:
- Hepatitis B or C infection
- Certain autoimmune diseases, including autoimmune hepatitis and primary biliary cholangitis
- Inherited metabolic conditions that lead to iron overload or copper buildup
- Fatty liver, which was previously referred to as nonalcoholic fatty liver disease (NAFLD) but is now called metabolic dysfunction-associated steatotic liver disease (MASLD)
- Long-term alcohol abuse
"Viral hepatitis infections can become chronic without a person knowing it, which is why screening is so important," says Dr. Victor. "Some of the other causes of liver disease, like the autoimmune diseases and metabolic issues, are fairly rare but can also occur without a person knowing."
The most common of these causes is metabolic-associated steatotic liver disease.
"It's estimated that up to one in two adults can meet criteria for MASLD, which is having greater than 5% fat in their liver," adds Dr. Victor. "Most of these individuals won't develop liver disease, though."
He adds that the key, then, becomes identifying who is experiencing liver inflammation and treating the issue before it leads to permanent damage.
"Liver disease doesn't cause physical symptoms until the damage has become severe," explains Dr. Victor. "And, when it's symptomatic, it's often irreversible damage. This is what we're trying to prevent."
Advanced liver disease symptoms include:
- Jaundice (yellowing of the skin and eyes)
- Abdominal swelling
- Easy and severe bruising
- Swelling in the legs and ankles
"So, the key really becomes early diagnosis, catching an issue with the liver before these symptoms arise," says Dr. Victor. "And we can do that by monitoring liver function and screening for viral hepatitis."
While not a sign of liver disease itself, fatty liver can increase the chance of developing chronic liver disease. To prevent liver damage, it helps to know your risk of this common issue.
The following health conditions increase the risk of developing metabolic-associated fatty liver disease:
- Type 2 diabetes
- High cholesterol
- Metabolic syndrome
- Polycystic ovarian syndrome (PCOS)
"Of those with fatty liver, only a small percentage end up with actual liver damage from it," adds. Dr. Victor. "It's why, if you have risk factors, you should talk to your doctor about having routine bloodwork done regularly."
The goal, as Dr. Victor mentions, is to catch a liver problem before it progresses into liver disease.
"We can do this through liver function tests, which are part of a person's annual comprehensive metabolic panel," explains Dr. Victor. "Through these routine blood tests, your primary care doctor can monitor the levels of liver enzymes and proteins, such as ALT, AST, bilirubin and alkaline phosphatase."
If these liver function tests are normal, it typically means the liver is healthy and in good shape.
"The scales of these tests have changed, though," warns Dr. Victor. "People who have been told their liver function looks normal in the past should look a little closer — at their ALT levels, in particular."
A normal ALT is around 20 for women and between 30 to 40 for men. Numbers higher than this are a sign of inflammation in the liver.
Liver function tests are part of a person's routine annual physical with their primary-care doctor, but it does take seeking out such care to keep tabs on your liver health. This is especially important if you have risk factors for fatty liver disease. And if you've been diagnosed with the disease, your doctor may do additional testing to assess the liver.
"There has been a call by the American Gastroenterology Association for people with metabolic associated fatty liver disease to undergo screening for advanced liver disease, via a FIB-4 blood test," says Dr. Victor. "If you are concerned or you've been told you have fatty liver and elevated liver enzymes, this test can determine if you're at risk for fibrosis or cirrhosis."
If blood tests indicate liver damage, special kinds of ultrasounds or MRI are used to confirm the damage and determine its severity. In complicated or advanced cases, liver biopsy may be required.
The first step of liver disease treatment is identifying and correcting its cause.
"Viral hepatitis can be a chronic infection that affects the liver without the person knowing it, so the goal is for people to get screened for hepatitis B and C," says Dr. Victor. "And treated for either of these, if needed."
In the U.S., adults under age 40 will have had the hepatitis B vaccine as part of routine childhood immunizations and are therefore protected. Most older adults aren't vaccinated against hepatitis B, so they will need to get screened at least once in their lifetime. Hepatitis B vaccination isn't advised for all adults, but your doctor may recommend it if you have certain risk factors.
Recent guideline changes now recommend hepatitis C screening for all adults.
"People haven't been checked for hepatitis C until recently," says Dr. Victor. "We have an effective therapy for it now, so the message is to get screened so that if you do have it, you can be treated for it."
If you're unclear whether you've been screened for hepatitis B or C, ask your doctor.
Treatment of fatty liver disease, the most common cause of liver disease, focuses on lifestyle changes.
"There are no FDA approved medications for metabolic-associated steatotic liver disease, but weight loss and a healthy diet are crucial," says Dr. Victor. "In fact, losing between 10-20% of body weight can remove fat from the liver and cure fatty liver disease."
Adopting a healthy diet includes cutting back on sugar, limiting or avoiding alcohol and eating plenty of whole, fresh foods. (Related: How to Eat Healthy When Ordering From a Delivery Service)
If liver disease is advanced and cirrhosis is present, it will need to be carefully monitored by your doctor or managed by a liver specialist — who can provide treatments that prevent the worsening of symptoms.
"Once a person has cirrhosis, it's not reversible but the disease itself is still manageable — as long as liver inflammation is controlled," says Dr. Victor. "If not well-managed, continued damage can ultimately lead to the liver becoming incapable of performing activities needed for the body to function optimally."
Complications of liver disease don't just affect the liver. They can affect the abdomen, lungs, brain, heart and more. And, if liver failure occurs, it can lead to death unless liver transplantation happens.
"Liver health is something everyone needs to be aware of," says Dr. Victor. "Monitoring it involves seeking regular care from your primary care doctor and addressing an issue if one arises. Ideally, we prevent liver disease from happening in the first place."