Overview
Hepatitis A is inflammation of the liver caused by the hepatitis A virus. It spreads through food and water contaminated with traces of faeces, and through close personal contact with an infected person.
Unlike hepatitis B and C, it never becomes a long-term infection. WHO states that almost everyone recovers fully and is then immune for life. The illness still matters because it can be severe in adults, particularly those over 50 or with existing liver disease.
Disease Summary
- Category
- Infectious Disease
- Cause
- Hepatitis A virus
- Transmission
- Contaminated food and water, and close personal contact
- Body System
- Liver
- Preventable
- Yes
- Curable
- No
Symptoms
Common Symptoms
Symptoms usually begin 14 to 28 days after infection. WHO reports that around 70% of children under six have no noticeable symptoms, while most older children and adults become visibly jaundiced.
Fever
The illness typically begins abruptly with fever and a general sense of being unwell.
Tiredness
Marked fatigue is one of the most consistent symptoms and often outlasts the others.
Loss of Appetite
Loss of appetite is listed by both WHO and CDC and can be pronounced.
Nausea, Vomiting and Stomach Discomfort
Discomfort is usually felt in the upper right side of the abdomen, where the liver sits.
Diarrhoea
Listed by both WHO and CDC among the symptoms of hepatitis A.
Dark Urine or Pale Stools
Urine the colour of strong tea and unusually pale stools are often noticed before the yellowing of the skin.
Jaundice
Yellowing of the skin and the whites of the eyes. WHO reports that only 10% of children under 6 develop it, against over 70% of older children and adults.
Joint Pain
Listed by CDC among the symptoms of hepatitis A.
Danger Signs
Seek urgent medical attention immediately if any of the following symptoms develop.
Deepening Jaundice With Confusion or Drowsiness
These are signs of acute liver failure, which WHO describes as rare but often fatal. This is a medical emergency.
Persistent Vomiting and Inability to Keep Fluids Down
Because treatment is supportive and rests on hydration, failure of oral intake is what turns home care into hospital care.
Unusual Bruising or Bleeding
A sign that the liver is no longer making clotting proteins properly.
Symptoms in an Adult Over 50 or With Existing Liver Disease
WHO states that older age groups have higher severity and more fatal outcomes.
Symptoms Returning After Apparent Recovery
WHO reports that 10% to 15% of symptomatic people have prolonged or relapsing symptoms for up to 6 months. This warrants reassessment.
Diagnosis
Exposure History and Timing
The incubation period is usually 14 to 28 days, which sets the window for identifying the source: contaminated food or water, a household contact, sexual contact or travel.
Examination for Jaundice and Liver Tenderness
Onset is usually abrupt with fever, tiredness, loss of appetite, nausea, abdominal discomfort, dark urine and then jaundice.
Blood Testing, Which Is Required
The types of viral hepatitis cannot be told apart by symptoms. Diagnosis rests on detecting hepatitis A specific antibodies in blood.
Distinguishing It From Other Causes of Jaundice
Other viral hepatitis, malaria, medicines and alcohol all cause jaundice, and treatment differs entirely.
Assessing Severity
WHO states that hospital admission is unnecessary in the absence of severe disease or acute liver failure, which makes that assessment the key decision.
Laboratory Tests
Hepatitis A IgM Antibody
The diagnostic test. A positive result indicates acute or recent infection. CDC states it is typically detectable from 5 to 10 days before symptoms start until about 6 months after.
Hepatitis A IgG or Total Antibody
A positive result indicates immunity, either from past infection or from vaccination. CDC states it is not helpful for diagnosing acute illness.
Liver Enzyme Test
A raised level reflects injury to liver cells. CDC states liver enzymes and bilirubin both aid the diagnosis.
Bilirubin
Raised bilirubin is what produces the jaundice and the dark urine. It is tracked to follow the course of the illness.
Hepatitis A Molecular Test
Detects the virus itself. Used mainly to investigate the source of an outbreak and link cases together.
Treatment
Supportive Care
WHO states there is no specific treatment for hepatitis A and that care focuses on hydration, nutrition and fluid replacement. Most people manage at home.
Avoiding Medicines That Stress the Liver
WHO explicitly advises avoiding medicines that are hard on the liver, because it is already inflamed. Tell your clinician everything you take, including herbal remedies and alcohol.
Hospital Care for Severe Disease
WHO states that admission is unnecessary in the absence of severe disease or acute liver failure, so hospital care is reserved for those who cannot keep fluids down or who show signs of liver failure.
Vaccination After Exposure
CDC states a dose of hepatitis A vaccine given within 2 weeks of exposure can prevent illness in unvaccinated people aged 12 months and older.
Immune Globulin After Exposure
Provides short-term protection within 2 weeks of exposure. CDC recommends giving it alongside the vaccine for people who are immunocompromised or have chronic liver disease.
Prevention
Hepatitis A vaccination
WHO recommends a first dose from a minimum age of 1 year. The vaccine is safe, effective and the most reliable protection available.
Safe drinking water
WHO lists adequate supplies of safe drinking water among the core prevention measures.
Proper disposal of sewage
WHO lists proper disposal of sewage within communities as a core measure, because the virus spreads by the faecal-oral route.
Handwashing with soap and water
WHO recommends regular handwashing before meals and after using the toilet. CDC adds after changing nappies and before preparing food.
Safer sex practices
WHO names safer sex practices, noting oral-anal contact specifically as a route of transmission.
Vaccination before travel
CDC warns that handwashing alone is not sufficient in areas where hepatitis A is common, so travellers should discuss vaccination before departure.
Risk Factors
Communities With Poor Sanitation
WHO links infection risk directly to unsafe water, poor sanitation and poor hygiene.
- Children in low- and middle-income settings, about 90% of whom are infected before age 10
- Households without a safe water supply
- Communities without proper sewage disposal
- Household members of an infected person
Adults Over 50 and People With Liver Disease
WHO states that severity and fatal outcomes rise with age.
- Adults aged 50 and over
- People with existing chronic liver disease
- People living with hepatitis B or hepatitis C
- People living with HIV
People in Unstable Housing and People Who Use Drugs
CDC identifies these groups in recent outbreaks.
- People experiencing homelessness
- People who inject or use drugs
- People in crowded temporary accommodation
- Anyone without reliable access to handwashing facilities
Travellers to Areas Where It Is Common
CDC names travel as a significant route of infection.
- Unvaccinated travellers to areas of high endemicity
- People visiting family in their country of origin
- Those anticipating close contact with an international adoptee
- Laboratory workers handling the virus
Complications
Acute Liver Failure
WHO states that hepatitis A rarely causes acute liver failure, and that when it does it is often fatal. This is the reason severe symptoms are taken seriously.
Prolonged or Relapsing Illness
WHO reports that 10% to 15% of symptomatic people have prolonged or relapsing symptoms for up to 6 months.
Hospital Admission
A significant proportion of people in recent outbreaks needed hospital care, largely because of dehydration and severe symptoms.
Prolonged Jaundice
A form in which the jaundice and itching persist for weeks longer than usual, though recovery is still complete.
Death
WHO reports that 35 569 people died from hepatitis A worldwide in 2023, accounting for 2.6% of deaths from viral hepatitis.
No Chronic Infection
Unlike hepatitis B and C, hepatitis A causes acute infection only and never becomes chronic. This is the single most reassuring fact about it.
When to Seek Medical Care
Yellowing of the Skin or Eyes, Dark Urine or Pale Stools
These signal liver involvement and are the point at which testing is indicated.
Within Two Weeks of a Known Exposure, If Unvaccinated
CDC states a single dose of hepatitis A vaccine within 2 weeks of exposure may prevent the illness. That window closes.
Persistent Vomiting or Inability to Stay Hydrated
Treatment rests on hydration, so failing to keep fluids down is a reason for medical care.
Confusion, Drowsiness or Worsening Jaundice
These suggest acute liver failure and are an emergency.
Symptoms in an Adult Over 50 or With Liver Disease, Hepatitis B or C, or HIV
Severity and the risk of liver failure are higher in these groups.
Prognosis
Almost Everyone Recovers Fully
WHO states that almost everyone recovers fully from hepatitis A with lifelong immunity. Symptoms usually settle within two months.
A Minority Take Longer
WHO reports prolonged or relapsing symptoms for up to 6 months in 10% to 15% of symptomatic people. Recovery is still complete.
Deaths Are Rare but Age-Dependent
WHO reports 35 569 deaths worldwide in 2023. Risk rises considerably in adults over 50 and in people with existing liver disease.
No Long-Term Liver Damage
Hepatitis A does not become chronic and does not cause cirrhosis or liver cancer.
Differential Diagnosis
Hepatitis B and Hepatitis C
Produce an identical picture of jaundice and fatigue. Only blood tests separate them, and the difference matters because those two can become chronic.
Malaria
Causes fever and jaundice and must be excluded in any endemic area, because it needs urgent specific treatment.
Hepatitis E
Another virus spread by contaminated water that causes an almost identical illness, and which is particularly dangerous in pregnancy.
Medicine or Herbal Remedy Damage to the Liver
Several medicines and traditional preparations cause jaundice, and the history of what has been taken is what reveals it.
Gallstones Blocking the Bile Duct
Cause jaundice with severe pain in the upper abdomen, separated by ultrasound of the abdomen.
References
World Health Organization: Hepatitis A
WHO fact sheet on transmission, symptoms, treatment, prevention and global burden.
CDC: Clinical Overview of Hepatitis A
Clinical course, risk groups, complications and management.
CDC: Hepatitis A Diagnosis and Testing
Which antibody tests to use and how to interpret the results.
CDC: Hepatitis A, Pink Book
Detailed chapter on the virus, clinical features, outbreaks and vaccination.
Frequently Asked Questions
Does hepatitis A become a long-term illness?
No. CDC states that hepatitis A causes acute infection only and never becomes chronic, unlike hepatitis B and C. WHO states that almost everyone recovers fully and has lifelong immunity afterwards.
How is hepatitis A caught?
WHO states it spreads mainly through eating food or drinking water contaminated with traces of faeces, and through direct contact with an infected person, including sexual contact. People can pass it on for up to two weeks before they feel ill.
Is there a treatment?
There is no specific treatment. WHO states care is supportive, focused on hydration and nutrition, and that medicines which stress the liver should be avoided. Most people recover at home within two months.
I have been exposed. Can anything stop me getting ill?
Possibly, if you act quickly. CDC states that a single dose of hepatitis A vaccine given within 2 weeks of exposure may prevent the illness in unvaccinated people aged 12 months and older. Immune globulin can also be given, particularly for people who are immunocompromised or have chronic liver disease.
Do I need the vaccine if I had hepatitis A as a child?
No, provided that is confirmed. One infection gives lifelong immunity, and a blood test for hepatitis A IgG antibody will show whether you are already protected.