Hepatitis diagnosis

Last updated Feb. 10, 2025, by Lindsey Shapiro, PhD
Fact-checked by Marta Figueiredo, PhD

Hepatitis — a general term to describe liver inflammation — can often be diagnosed based on a thorough physical exam and results of blood tests. Imaging studies and a liver biopsy may support a diagnosis and determine the extent of tissue scarring (fibrosis) and damage to the liver to help doctors make appropriate treatment decisions.

Hepatitis can have many possible causes, including autoimmune reactions or toxins (such as drugs or alcohol) that damage the liver, but most often occurs due to viral infections. Viral hepatitis — which includes hepatitis A, B, C, D, and E — is one of the most common liver diseases, estimated to affect more than 300 million people worldwide. It is also a leading cause of morbidity and mortality, or poor health and death.

In some cases, the disease leads to mild and acute illness that resolves on its own, but in others, it can lead to chronic liver inflammation that drives more serious damage to the organ over time.

Accurately diagnosing hepatitis as soon as possible is essential for starting treatment early, which can potentially avoid serious long-term consequences, such as irreversible scarring that impairs liver function (cirrhosis), liver cancer, and liver failure.

Importance of early diagnosis

Acute hepatitis, where liver inflammation lasts less than six months, often does not have any symptoms or is accompanied by mild symptoms that clear up in the short term without causing damage to the liver.

However, for some people, especially in the case of hepatitis B, C, and D, a chronic form of the disease can develop that eventually causes serious harm to the liver. Still, many people won’t know they have chronic hepatitis for years or decades because it often doesn’t cause symptoms until substantial liver damage has accumulated.

An early and accurate hepatitis diagnosis is critical for making sure the right treatments are initiated that can address the underlying cause of hepatitis and prevent irreversible liver damage. In addition, because some forms of viral hepatitis can be transmitted through contact with bodily fluids, identifying the disease may also help prevent its transmission to others.

People should reach out to a medical professional if they think they’ve been exposed to a hepatitis virus, and those who are considered to have an increased risk for contracting the disease, including certain healthcare professionals and injectable drug users, should talk with a doctor about how often they should be screened.

Individuals should also always speak with a healthcare professional if they notice any possible signs or symptoms of hepatitis, which may include:

fatigue or feeling unusually tired
malaise, or a general feeling of being unwell
flu-like symptoms, including a low-grade fever, especially in viral hepatitis
abdominal discomfort
jaundice, a yellowing of the skin and whites of the eyes
dark urine
pale-colored stools
itchy skin, or pruritus
nausea or vomiting
appetite loss.

Key diagnostic tools and methods

In the presence of possible symptoms of hepatitis, a doctor will first collect a thorough medical history, during which they’ll ask about symptoms and their duration, as well as several factors that may influence the risk of hepatitis, including:

possible or known exposures to hepatitis viruses
history of prescribed and over-the-counter medications and herb supplements
possible exposure to industrial chemicals, pesticides, or other environmental toxins
history of alcohol use
injection drug use
other medical conditions
vaccination history.

They’ll also perform a physical exam to look for clinical signs of liver damage, including jaundice and an enlarged liver.

If these evaluations point to hepatitis, doctors may run a series of medical tests, including blood tests, imaging scans, and a liver biopsy, to confirm the diagnosis, identify the disease’s underlying cause, and determine the degree of liver damage. Information from these tests will also guide decisions regarding the best way to treat the condition in order to prevent additional liver problems.

Blood tests

Blood tests are often sufficient to establish a hepatitis diagnosis, particularly for viral hepatitis. Through a series of tests, doctors can identify signs of liver problems, the presence of hepatitis viruses, or other possible hepatitis causes.

These tests may assess:

levels of liver enzymes or other markers of liver function and damage
the presence of antibodies against hepatitis viruses
the total amount of a hepatitis virus, called viral load
the specific strain of a hepatitis virus that’s present
the presence of self-reactive antibodies associated with autoimmune hepatitis
levels of toxins, alcohol, and legal and illegal drugs that can cause hepatitis.

If doctors suspect a person may have hepatitis, they may start by running a series of blood tests, called the antibody and antigen panel, for the most common causes of hepatitis — the hepatitis A, B, and C viruses.

Antibodies are proteins generated by the immune system to attack harmful invaders such as viruses, while antigens are the molecules that stimulate an immune response and are targeted by antibodies.

The specific antibodies or antigens that are present in the blood can help doctors understand if a person has an active infection with a hepatitis virus and is likely contagious, if they’ve had one in the past but are no longer contagious, or if they’re immune from infection with a virus due to past vaccination or infection.

Hepatitis A tests look for two types of antibodies against the hepatitis A virus that can indicate if a person has an acute infection or is immune from a prior infection or vaccination.
Hepatitis B screening involves three tests that look for antibodies against the hepatitis B virus (HBV) as well as certain HBV antigens. Together, these tests tell whether a person is actively contagious, if they have an acute or chronic infection, or if they’re immune from a prior infection or vaccination.
Hepatitis C tests look for antibodies against the hepatitis C virus, but a positive result cannot necessarily distinguish between a current or past, resolved infection, so viral load testing will be necessary.

Hepatitis D virus only infects people who are already infected with HBV, and as such, doctors won’t look for it unless a person has already been diagnosed with hepatitis B. Hepatitis E is less common than other forms of viral hepatitis, but there are also antibody tests for it.

If antibody tests suggest an active viral hepatitis infection, doctors may perform viral load testing, which measures RNA, the type of genetic material found in hepatitis viruses, and determines how much of the virus is present in the bloodstream or stool.

The presence of viral RNA suggests an active infection, and the higher the levels, the more infectious a person is. Doctors also use viral load testing while managing viral hepatitis to assess how well treatment has worked.

Hepatitis viruses are constantly developing new genetic mutations to help them survive, so there are several strains of each hepatitis virus. Blood tests can also be used to perform viral genotyping, where the viral strain that’s infecting a person is determined. As some viral strains are more responsive to antiviral treatments than others, this can help doctors decide the best treatment strategy.

Imaging studies

While blood tests alone can often diagnose viral hepatitis, doctors may also order imaging tests to further examine the extent of damage to the liver and look for complications such as hepatocellular carcinoma (HCC), a type of liver cancer that is most commonly caused by chronic infections with the hepatitis B or C viruses.

If blood tests weren’t conclusive for identifying hepatitis or its cause, imaging tests can also help establish the diagnosis or rule out other causes of liver disease.

Imaging studies used in hepatitis diagnosis may include:

abdominal ultrasound
MRI or CT scans
elastography.

Ultrasounds use high-frequency sound waves to generate images of internal organs. An abdominal ultrasound can show signs of liver inflammation or other abnormalities in the liver’s shape and structure. CT or MRI scans may be ordered if a more detailed picture of the liver is required.

Elastography uses low-frequency vibrations during an ultrasound or MRI to measure the stiffness of specific organs and tissues, with more stiffness indicating a greater degree of tissue scarring. A type of elastography called vibration-controlled transient elastography, which is usually performed using a device known as FibroScan, is commonly used to assess liver fibrosis. This test helps doctors understand how damaged the liver is from hepatitis, and often eliminates the need for a liver biopsy.

Liver biopsy

A liver biopsy, where a small sample of liver tissue is collected and sent to a lab for analysis, may also be used in some cases to help doctors understand the degree of liver fibrosis and damage caused by hepatitis. Due to its more invasive nature, this procedure is typically ordered only if noninvasive tests were unable to provide conclusive results.

Liver biopsy supports a viral hepatitis diagnosis, but it is considered essential for both diagnosis and staging of autoimmune hepatitis. While blood tests can show the presence of self-reactive antibodies associated with autoimmune hepatitis, they are not definitive and not all patients will test positive for them. Only a liver biopsy can show the hallmark changes in liver tissue caused by autoimmune hepatitis.

The procedure is usually done by inserting a small needle through the abdomen and into the liver after administration of a local anesthetic. It’s a safe procedure when done by an experienced healthcare professional, but it can come with certain risks, including:

pain at the biopsy site
internal bleeding
infection
accidental damage to nearby organs.

Diagnostic challenges

The symptoms of hepatitis can overlap with a number of other liver diseases, and doctors may have to rule out these differential diagnoses before establishing a diagnosis of hepatitis. Conditions that clinically overlap with various forms of hepatitis include:

liver abscesses (pus-filled areas)
HCC
acute and chronic forms of cholangitis
fatty liver disease
cancer or inflammation of the pancreas
inflammation of the gallbladder
other conditions of the gastrointestinal system, including gastroenteritis, open sores in the stomach or upper part of the small intestine, or bowel obstructions
alpha-1 antitrypsin deficiency
Wilson disease.

In addition to distinguishing hepatitis from other forms of liver disease, doctors will have to distinguish between the different underlying causes of hepatitis, as this will guide treatment decisions.

If initial screening tests suggest a possible problem with the liver, primary care physicians should work with liver specialists (hepatologists) or infectious disease experts who understand how to diagnose hepatitis and determine its cause.

However, hepatitis screening, vaccination, and treatment may be more difficult in low- or middle-income countries with less access to healthcare resources.

Hepatitis screening recommendations

Diagnosing hepatitis can also be complicated by the fact that it often doesn’t have any symptoms until substantial liver damage has occurred, so the disease can progress without being identified for many years. Routine screening of people at higher risk of hepatitis even in the absence of symptoms can help diagnose the disease in these cases.

The U.S. Centers for Disease Control and Prevention generally recommends that all adults in the United States get screened for hepatitis B and C at least once in their lifetime, regardless of their risk.

In turn, people with an increased risk may need to be tested periodically throughout their lives. This may include people who:

have a history of sexually transmitted infections or multiple sex partners
are currently or have been incarcerated
have close contact to people with hepatitis
live in areas with a high hepatitis infection prevalence
have a current or past history of injecting drugs
have certain medical conditions, including human immunodeficiency virus, or HIV
receive maintenance dialysis, a procedure meant to substitute the natural functions of the kidneys when they are not working normally
were born male and have sex with men
were born to people with a known hepatitis infection.

There are no routine screening guidelines for hepatitis A, D, or E, but individuals who may have been exposed or are experiencing symptoms should reach out to a doctor for testing.

People should talk with their doctors about their individual risk level for contracting viral hepatitis and determine the most appropriate screening plan for their situation.

As with any contractable disease, prevention is the best way to avoid the serious complications of hepatitis. There are effective vaccines available to protect against hepatitis A and B. The World Health Organization recommends these vaccines for all people to control the spread of viral hepatitis.

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