Original Article:
http://www.mayoclinic.com/invoke.cfm?id=DS00397&dsection=1
Overview
Hepatitis A is a highly contagious liver infection caused by the hepatitis A virus (HAV). Although not usually as serious as other types of viral hepatitis, hepatitis A causes inflammation that affects your liver’s ability to function.
You’re most likely to contract hepatitis A from contaminated food or water or from close contact with someone who’s already infected — even if that person doesn’t appear sick. Some people who are infected never develop signs and symptoms, but others may feel as if they have a severe flu.
Mild cases of hepatitis A don’t require treatment, and most people who are infected recover completely with no permanent liver damage. Unlike hepatitis B and C, hepatitis A doesn’t develop into chronic hepatitis or cirrhosis — both potentially fatal conditions.

Practicing good hygiene — including washing your hands often — is one of the best ways to protect against hepatitis A. Effective vaccines are available for people who are most at risk.
By Mayo Clinic staff