After contracting hepatitis A virus, or HAV, symptoms don’t appear right away. The virus has an incubation period of two to seven weeks before any symptoms occur, according to the Centers for Disease Control (CDC), with the average incubation period lasting 28 days. However, some people, especially young children, may catch the virus without even knowing it because symptoms never develop. In fact, about 70 percent of hepatitis A cases in children under six years old are asymptomatic, according to the CDC. Jaundice, or the yellowing of the skin and eyes, occurs in more than 70 percent of hepatitis A cases in older children and adults, according to the World Health Organization (WHO). Other symptoms that develop are generally mild and may include:

Low-grade feverFatigueLoss of appetiteNausea and vomitingDiarrheaAbdominal painUpset stomachPruritus (itching)Dark-yellow urine and light- or clay-colored stoolsMuscle aches and joint pain

Symptoms usually persist for less than two months, but some people may be sick for up to six months, according to the CDC.

Hepatitis A Diagnosis

To diagnose hepatitis A, your doctor will first get your medical history and ask about your recent symptoms. Next, your doctor will likely conduct a physical exam to see if your liver is enlarged and tender. Finally, your doctor will take your blood to be analyzed. You have hepatitis A if the blood tests reveal elevated levels of:

IgM and IgG antibodies specific to the hepatitis A virusLiver enzymes, particularly the enzyme alanine aminotransaminase (ALT)

Hepatitis A Complications

Unlike other types of viral hepatitis, hepatitis A doesn’t become chronic and generally doesn’t cause long-term liver damage. But it can cause complications. Some people with hepatitis A experience a relapse, during which their infection returns and they experience symptoms again. This usually happens about two to three months after the initial infection, and it occurs in 3 to 20 percent of children who get hepatitis A, according to a 2000 article in the journal Vaccine. Cholestasis, or cholestatic hepatitis, is another potential complication of hepatitis A. It is the result of bile buildup, and it causes persistent jaundice and intense itching. In rare cases, people with hepatitis A may suffer from fulminant and subfulminant hepatitis, which can rapidly cause liver failure. This typically affects people with a pre-existing liver disease or a weakened immune system, according to the UK’s National Health Services. Symptoms of liver failure include:

Hepatitis-like symptoms, including jaundice, nausea, and vomitingBruising and bleeding easilyEdema, the buildup of fluid in the extremities, and ascites, the buildup of fluid in the abdomenHair lossDisorientation or confusion, also called hepatic encephalopathySleepiness

The fatality rate of fulminant hepatitis is about 80 percent, according to the Vaccine report.