Hepatitis A is a highly contagious liver infection caused by the hepatitis A virus. Unlike hepatitis B and C, it does not become a chronic condition. Most people recover fully within a few weeks to months, and once you’ve had it, you’re immune for life. In 2023, the CDC estimated roughly 3,300 hepatitis A infections occurred in the United States, with 85 reported deaths.
How Hepatitis A Spreads
The virus spreads through the fecal-oral route, which means it gets into your body when you ingest something contaminated with traces of infected stool. That sounds dramatic, but in practice it happens through ordinary-seeming situations: eating food prepared by someone who didn’t wash their hands after using the bathroom, drinking contaminated water, eating raw shellfish harvested from polluted water, or close contact (including sexual contact) with someone who’s infected.
The virus is remarkably durable. Depending on conditions, it can survive on surfaces for months. Bloodborne transmission is possible but uncommon. This environmental resilience is a big reason why outbreaks can ripple through restaurants, daycare centers, and communities with limited sanitation infrastructure.
Symptoms and Timeline
After exposure, there’s typically an incubation period of about two to four weeks before symptoms appear. Not everyone gets noticeably sick. Children under six often have no symptoms at all, while older children and adults are more likely to feel the full impact.
When symptoms do appear, they usually start with a flu-like phase: fatigue, nausea, loss of appetite, low-grade fever, and abdominal pain, particularly in the upper right side where the liver sits. Within a few days to a week, the more recognizable signs of liver involvement can show up. These include jaundice (yellowing of the skin and whites of the eyes), dark urine, and pale or clay-colored stools. Some people also experience intense itching.
The illness typically lasts anywhere from a few weeks to a couple of months. A small number of people experience a relapsing course where symptoms improve and then return, but even in these cases the infection eventually clears on its own.
How It Differs From Hepatitis B and C
The three main types of viral hepatitis differ in important ways. Hepatitis A spreads through contaminated food and water and never becomes chronic. Hepatitis B spreads through blood and body fluids and can become a lifelong infection in some people, requiring antiviral treatment. Hepatitis C spreads primarily through blood exposure, becomes chronic in most people who contract it, but can now be cured with medication.
Both hepatitis A and B are preventable with vaccines. Hepatitis C has no vaccine but is curable with direct-acting antiviral treatment. Hepatitis A is the only one of the three that your body always clears completely on its own.
Diagnosis
A blood test is the only way to confirm hepatitis A. The key marker is a specific antibody called IgM anti-HAV, which your immune system produces during an active infection. This antibody shows up about five to ten days before symptoms start and remains detectable for roughly six months after infection.
A different antibody, IgG anti-HAV, appears around the time symptoms begin and stays in your blood permanently. It signals either past infection or vaccination and is what gives you lifelong immunity. If your blood shows IgG but no IgM, you had hepatitis A at some point (or were vaccinated) but don’t have an active infection.
Treatment and Recovery
There is no specific medication that kills the hepatitis A virus. Treatment is entirely supportive: rest, staying well hydrated, and eating a balanced diet. Most people recover at home without any medical intervention beyond managing symptoms like nausea or fatigue. People with severe cases may need to be hospitalized, but this is uncommon.
During recovery, your liver is working to heal itself. Avoiding alcohol is important because it adds stress to an already inflamed liver. Some over-the-counter medications, particularly acetaminophen (Tylenol), can also be hard on the liver and may need to be limited or avoided. Your healthcare provider can advise on what’s safe during your recovery period.
When Hepatitis A Becomes Dangerous
For most people, hepatitis A is an unpleasant but temporary illness. In rare cases, it can progress to acute liver failure, a life-threatening condition where the liver stops functioning. Among those who do develop acute liver failure from hepatitis A, roughly half either die or require an emergency liver transplant.
The people most at risk for severe outcomes include adults over 40, people with weakened immune systems, and those who already have chronic liver disease (from hepatitis B, hepatitis C, alcohol use, or other causes). Having a pre-existing liver condition and then contracting hepatitis A is a particularly dangerous combination. This is one of the main reasons vaccination is strongly recommended for anyone with chronic liver disease.
Who’s at Higher Risk of Infection
International travelers face the highest exposure risk. Hepatitis A is common in many parts of the world, and experts recommend that all unvaccinated people traveling outside the United States consider getting vaccinated regardless of destination. The traditional advice focused on countries with high or intermediate rates of infection, but foodborne transmission can happen even in lower-risk countries.
Other groups at elevated risk include people experiencing homelessness, people who use drugs (injected or not), men who have sex with men, and household contacts of someone with a known infection. Families adopting children internationally should also ensure household members are vaccinated, ideally at least 60 days before the child arrives.
Vaccination
The hepatitis A vaccine is the most effective way to prevent infection. It’s recommended as a routine childhood vaccine, given to children between 12 and 23 months of age. The standard series involves two shots spaced six months apart. A combination vaccine that also covers hepatitis B requires three shots over six months.
Adults who were never vaccinated as children can get the vaccine at any age. If you’re planning international travel and haven’t been vaccinated, the first dose should go in as soon as the trip is being considered. Adults over 40, people who are immunocompromised, and those with chronic liver disease should prioritize getting vaccinated early because their immune response may be slower or less robust. Pregnant women traveling to higher-risk areas or those with chronic liver disease or HIV are also recommended to receive the vaccine if they haven’t previously.
For infants too young for the routine schedule (6 to 11 months), a dose can be given before international travel, though it won’t count toward the standard two-dose series and will need to be repeated later.