Viral Hepatitis

Viral hepatitis is inflammation of the liver caused by one of several hepatitis viruses. The five main types — hepatitis A, B, C, D, and E — differ significantly in how they are transmitted, how long they last, and what treatment, if any, is needed. Some cause acute illness that resolves on its own; others can become chronic infections that persist for years and lead to serious liver complications if untreated.

Viral hepatitis is among the most common causes of liver disease worldwide. Globally, hepatitis B and C account for the majority of chronic liver disease, cirrhosis, and hepatocellular carcinoma. Hepatitis A and E are primarily acute illnesses with fecal-oral transmission, while hepatitis D only occurs in people already infected with hepatitis B.

Types of viral hepatitis

Hepatitis A (HAV) A self-limiting acute infection transmitted through contaminated food or water. It does not cause chronic liver disease. Most people recover fully within two to three months, and infection confers lifelong immunity. A safe and effective vaccine is available.

Hepatitis B (HBV) Transmitted through blood, sexual contact, and from mother to child during birth. Acute hepatitis B resolves on its own in most adults, but a proportion — particularly those infected at birth or in early childhood — develop chronic infection. Chronic hepatitis B can lead to cirrhosis and liver cancer over decades. Effective vaccines and antiviral treatments are available.

Hepatitis C (HCV) Transmitted primarily through blood-to-blood contact, most commonly through shared injecting equipment. There is no vaccine. Acute hepatitis C is often asymptomatic, and the majority of people develop chronic infection if untreated. Highly effective oral antiviral treatments now cure hepatitis C in over 95% of cases.

Hepatitis D (HDV) Only infects people who have hepatitis B, either as a co-infection (acquired at the same time) or superinfection (acquired after). It worsens the course of hepatitis B. Prevention relies on hepatitis B vaccination. Antiviral treatments for HDV are limited but developing.

Hepatitis E (HEV) Similar to hepatitis A in transmission (fecal-oral route, contaminated water) and clinical course — usually self-limiting. Most common in parts of Asia, Africa, and Central America. In immunocompromised individuals, hepatitis E can become chronic. A vaccine exists but is not widely available outside China.

Symptoms

Acute viral hepatitis of any type can produce similar symptoms, though many infections — particularly hepatitis C and hepatitis B in adults — are initially asymptomatic. When symptoms occur they typically include:

• Fatigue and general malaise — often the earliest and most persistent symptom
• Nausea, vomiting, and loss of appetite
• Right upper abdominal discomfort
• Low-grade fever, particularly early in the illness
• Dark urine and pale stools — early signs of bilirubin accumulation
• Jaundice — yellowing of the skin and whites of the eyes
• Itching (pruritus)
• Joint pain — more common in hepatitis B

Symptoms of acute hepatitis typically develop two to twelve weeks after exposure, depending on the virus. Chronic hepatitis B and C often produce no symptoms for years or decades, with liver damage accumulating silently until advanced disease develops.

Seek urgent medical attention if you experience:

• Progressive jaundice
• Confusion, drowsiness, or personality change (signs of hepatic encephalopathy)
• Abdominal swelling
• Unusual bleeding or bruising

These may indicate acute liver failure or decompensated chronic liver disease, both of which require emergency care.

Diagnosis

Viral hepatitis is diagnosed through blood tests. Initial assessment typically includes:

Liver function tests ALT and AST are elevated in active hepatitis, reflecting liver cell injury. Bilirubin rises with jaundice. The degree of elevation and the pattern of abnormality help guide the differential diagnosis. Albumin and INR assess liver synthetic function and are important markers of severity.

Viral hepatitis serology panel Specific antibody and antigen tests identify the causative virus:

Additional tests including viral load quantification, genotyping, and liver fibrosis assessment are used when chronic infection is confirmed to guide treatment decisions.

Treatment

Treatment depends on the specific virus and whether infection is acute or chronic.

Hepatitis A and E Supportive care only — rest, hydration, avoiding alcohol and hepatotoxic medications. No specific antiviral treatment exists. Almost all cases resolve fully without intervention.

Hepatitis B (acute) Most acute hepatitis B in adults resolves without treatment. Antiviral therapy is considered in severe acute cases. Monitoring is needed to confirm resolution and identify the small proportion who progress to chronic infection.

Hepatitis B (chronic) Long-term antiviral therapy — most commonly with tenofovir or entecavir — suppresses viral replication and reduces the risk of cirrhosis and liver cancer. Treatment is typically lifelong but well-tolerated. It does not cure infection but controls it effectively.

Hepatitis C (chronic) Direct-acting antiviral (DAA) regimens taken orally for 8–12 weeks cure hepatitis C in over 95% of patients, regardless of genotype or stage of liver disease. Treatment is recommended for all people with chronic hepatitis C. Early treatment prevents progression to cirrhosis and eliminates transmission risk.

Hepatitis D Management focuses on treating the underlying hepatitis B. Pegylated interferon has historically been the main treatment option; newer antiviral agents are under evaluation.

Prevention

Vaccination is the most effective prevention strategy where available. The hepatitis A vaccine is given as a two-dose series; the hepatitis B vaccine as a three-dose series — and vaccination against hepatitis B also protects against hepatitis D. There is no vaccine for hepatitis C.

Additional prevention measures include safe food and water practices (hepatitis A and E), safe sex and barrier contraception (hepatitis B and C), not sharing injecting equipment (hepatitis C and B), and screening of blood products (hepatitis B and C). Post-exposure prophylaxis with hepatitis B immunoglobulin and vaccine can prevent infection after a known high-risk exposure.

FAQ

What is the difference between hepatitis A, B, and C? Hepatitis A is a short-term infection that always resolves and never becomes chronic. Hepatitis B can be acute or chronic and has an effective vaccine. Hepatitis C is usually chronic if untreated but is now curable with antiviral medication. The viruses differ in transmission route, duration, severity of long-term risk, and available treatments.

Can viral hepatitis be cured? It depends on the type. Hepatitis A and E resolve on their own without treatment. Hepatitis C can be cured in over 95% of cases with current antiviral regimens. Hepatitis B cannot currently be cured but can be effectively controlled with long-term antiviral therapy. Hepatitis D is the most difficult to treat.

Is viral hepatitis always symptomatic? No. Many people with hepatitis B and C have no symptoms for years, especially in the chronic phase. Hepatitis A and E more commonly cause symptomatic illness in adults, but children with hepatitis A are often asymptomatic. Abnormal liver enzymes on routine blood tests are frequently the first clue to an unsuspected hepatitis infection.

Related biomarkers

Key lab markers in viral hepatitis include ALT, AST, and bilirubin for assessing liver injury and function, and specific serology tests — Hepatitis A Ab Total, Hepatitis A Ab IgM, Hepatitis B Surface Antigen, Hepatitis B Core Ab, Hepatitis B Surface Ab, and Hepatitis C Ab — for identifying the causative virus and immune status. Tracking these markers over time in HealthMatters supports monitoring of disease activity, treatment response, and recovery.