Hepatitis A
A contagious viral liver infection spread mainly through contaminated hands, food, water, or close contact with an infected person.
What causes Hepatitis A?
Hepatitis A is caused by the hepatitis A virus. It spreads by the fecal-oral route, including close personal contact and food or water contaminated with tiny amounts of stool.
Symptoms and what to notice
Many young children have no symptoms. Older children and adults may develop fatigue, loss of appetite, nausea, vomiting, abdominal pain, fever, dark urine, pale stools, joint pain, and jaundice.
How long can it last?
Symptoms usually begin 15 to 50 days after exposure, averaging about 28 days. Illness often lasts several weeks, but fatigue or relapsing symptoms can persist for months. Hepatitis A does not become chronic.
How serious is Hepatitis A?
Most people recover completely, but fulminant liver failure and death can occur, especially in older adults and people with chronic liver disease. Dehydration and prolonged cholestatic or relapsing illness are additional complications.
Treatment and management
There is no hepatitis A-specific antiviral. Treatment is supportive with fluids, nutrition, symptom management, and avoidance of alcohol or medicines that may further injure the liver unless a clinician approves them. Severe liver failure requires hospital and specialist care.
Vaccine: who and when?
Products: Havrix and Vaqta are inactivated single-antigen hepatitis A vaccines given as two doses to eligible people age 12 months and older. Twinrix combines hepatitis A and hepatitis B vaccines for adults age 18 and older and is given as a three-dose standard series or an approved accelerated series with a later booster.
Cost note: Cost varies by product, provider, insurance, and eligibility. Routine childhood vaccination is available through the Vaccines for Children program for eligible children, and many recommended vaccines are covered in network without cost sharing.
Trusted source
Patient cost varies by insurance, provider, location, and eligibility. Coverage and public-health access differ, so listed prices are examples rather than guaranteed patient prices. This page is for general education and does not replace individualized medical advice, diagnosis, vaccination assessment, or treatment.
Hepatitis A: Symptoms, Causes, Treatment, Prevention, and Vaccine Information
Hepatitis A is an acute infection of the liver. Unlike hepatitis B or C, it does not create a lifelong chronic infection, but the acute illness can be prolonged and occasionally life-threatening. People can shed the virus before jaundice or other obvious symptoms appear, which allows outbreaks to spread through households, childcare settings, food handling, sexual contact, homelessness networks, and communities with limited sanitation. Vaccination is highly effective and is the best prevention.
Important: This page is for general education. It does not replace diagnosis, treatment, vaccination advice, or emergency care from a qualified healthcare professional.
Quick Facts
| Topic | Current information |
|---|---|
| Cause | Hepatitis A is caused by the hepatitis A virus. It spreads by the fecal-oral route, including close personal contact and food or water contaminated with tiny amounts of stool. |
| Main symptoms | Many young children have no symptoms. Older children and adults may develop fatigue, loss of appetite, nausea, vomiting, abdominal pain, fever, dark urine, pale stools, joint pain, and jaundice. |
| Typical course | Symptoms usually begin 15 to 50 days after exposure, averaging about 28 days. Illness often lasts several weeks, but fatigue or relapsing symptoms can persist for months. Hepatitis A does not become chronic. |
| Treatment | There is no hepatitis A-specific antiviral. Treatment is supportive with fluids, nutrition, symptom management, and avoidance of alcohol or medicines that may further injure the liver unless a clinician approves them. Severe liver failure requires hospital and specialist care. |
| Vaccine status | Products: Havrix and Vaqta are inactivated single-antigen hepatitis A vaccines given as two doses to eligible people age 12 months and older. Twinrix combines hepatitis A and hepatitis B vaccines for adults age 18 and older and is given as a three-dose standard series or an approved accelerated series with a later booster. |
History and Public-Health Importance
Recognition of infectious jaundice predates identification of the hepatitis A virus. Laboratory methods and vaccine development transformed prevention during the late twentieth century. Universal U.S. childhood vaccination beginning at age one sharply reduced disease, yet outbreaks still occur among unvaccinated adults. Public-health response combines vaccination, immune globulin for selected exposed people, sanitation, food-safety investigation, and rapid notification of contacts.
What Causes Hepatitis A?
Hepatitis A is caused by the hepatitis A virus. It spreads by the fecal-oral route, including close personal contact and food or water contaminated with tiny amounts of stool.
The virus is present in stool and can reach another person through unwashed hands, contaminated food or water, diaper care, shared living conditions, or close sexual contact. A person is most infectious during the two weeks before jaundice begins and early in illness. Ordinary cooked food is safe when handled hygienically, but foods contaminated after cooking can transmit infection. Travelers to areas with higher transmission face additional risk.
Symptoms and Typical Course
Many young children have no symptoms. Older children and adults may develop fatigue, loss of appetite, nausea, vomiting, abdominal pain, fever, dark urine, pale stools, joint pain, and jaundice.
Young children frequently have mild or unrecognized infection. Adults are more likely to have fatigue, nausea, abdominal discomfort, dark urine, and jaundice. Symptoms generally resolve, but about 10% to 15% of symptomatic people can have prolonged or relapsing illness for up to several months. Recovery usually produces lasting immunity.
Complications and Who Is at Higher Risk
Most people recover completely, but fulminant liver failure and death can occur, especially in older adults and people with chronic liver disease. Dehydration and prolonged cholestatic or relapsing illness are additional complications.
Acute liver failure is rare but more likely in older adults and people with chronic liver disease. Severe vomiting can cause dehydration. Cholestatic hepatitis can produce prolonged jaundice and itching, while relapsing disease causes symptoms and abnormal liver tests to recur. Hepatitis A does not cause cirrhosis or liver cancer through chronic infection.
How It Is Diagnosed
Symptoms alone cannot distinguish hepatitis A from other liver diseases. Diagnosis uses a blood test for IgM antibody to hepatitis A virus, interpreted with liver enzymes and clinical findings. A positive total antibody without IgM can indicate past infection or vaccination rather than current disease. Suspected cases should be reported to public health so exposed contacts can be protected promptly.
Treatment and Recovery
There is no hepatitis A-specific antiviral. Treatment is supportive with fluids, nutrition, symptom management, and avoidance of alcohol or medicines that may further injure the liver unless a clinician approves them. Severe liver failure requires hospital and specialist care.
Rest, hydration, and adequate nutrition are central. A clinician should review prescription, over-the-counter, and herbal products because the inflamed liver may be more vulnerable to toxicity. Alcohol should be avoided. Hospital care may be needed for persistent vomiting, dehydration, bleeding problems, confusion, or signs of acute liver failure. Transplant evaluation is occasionally required.
Vaccine Information
Products: Havrix and Vaqta are inactivated single-antigen hepatitis A vaccines given as two doses to eligible people age 12 months and older. Twinrix combines hepatitis A and hepatitis B vaccines for adults age 18 and older and is given as a three-dose standard series or an approved accelerated series with a later booster.
CDC recommends routine vaccination for children at 12 through 23 months, catch-up vaccination through age 18, adults at increased risk, people at increased risk of severe disease, and anyone requesting protection. Havrix and Vaqta use age-specific formulations and a two-dose schedule. Twinrix protects adults against both hepatitis A and B. After exposure within the previous two weeks, vaccine and sometimes immune globulin can prevent or reduce illness depending on age, immune status, liver disease, and prior vaccination.
Prevention
Complete vaccination, wash hands after toileting or diaper changes and before preparing food, use safe water, and follow food-safety practices. People with hepatitis A should avoid preparing food for others while infectious and follow public-health guidance about work or school. Travelers should be vaccinated before departure whenever possible.
When to Seek Medical Care
Seek care for jaundice, dark urine, persistent vomiting, severe abdominal pain, confusion, unusual bleeding, or possible exposure in a person with chronic liver disease. Contact public health or a clinician quickly after a known exposure because postexposure protection is time-sensitive.
Frequently Asked Questions
Does hepatitis A become chronic?
No. The virus does not establish chronic infection, although symptoms can relapse or last for months.
Can vaccination help after exposure?
Yes. Vaccine given within two weeks can provide postexposure protection for many people; immune globulin is added or used in selected situations.
Can food spread hepatitis A?
Yes, when contaminated by infected hands or unsafe water. Proper hygiene and vaccination greatly reduce risk.
Which vaccines are used in the United States?
Havrix and Vaqta protect against hepatitis A alone. Twinrix combines hepatitis A and hepatitis B protection for adults.
Key Takeaway
Hepatitis A is preventable, never chronic, and sometimes severe. Vaccination and rapid postexposure action are far more reliable than trying to identify infectious people by symptoms alone.
Medical, treatment, and vaccine information was reviewed against official U.S. public-health guidance available through September 2026.