IStock Photo 627415 © Grafissimo

It's no fun having hepatitis. Your liver—the largest organ in your body besides your skin—swells up, perhaps until your abdomen is tender to the touch. In addition to feeling generally sick and feverish, you might lose your appetite or throw up. Your skin might turn yellow with jaundice. Your joints might ache. If it lasts long enough, hepatitis can permanently damage your liver.

The cause of your misery could be a virus, bacteria, toxins, various drugs, long-term alcohol use, or certain diseases. If you have an acute case, you could be feeling better in a few weeks or months. If you're one of the unlucky ones to develop chronic hepatitis, though, you'll be sick for at least six months—possibly for the rest of your life.

Three types of viral hepatitis are common in the United States: A, B, and C. And viral hepatitis is one of the four deadliest communicable diseases in the country.

If you had to pick one, hepatitis A (HAV) might be the way to go. Typically spread by contact with food or other objects contaminated with infected fecal matter, this is the one you hear about in the news when a restaurant is implicated in an outbreak. It can be mild or severe, but it doesn't become chronic, and most people recover on their own.

Since a vaccine became available in 1995, the infection and death rates of hepatitis A have dropped to a 40-year low. Now, the odds of being diagnosed with hepatitis A in a year are 1 in 83,330. If you have it, the odds you'll die of it in a year are 1 in 322.4.

Hepatitis B (HBV) is the most common of the three, with the odds of being diagnosed in a year at 1 in 62,500, which is nearly the same as the odds a person in Lincoln, Nebraska will be murdered in a year (1 in 62,890). Even though deaths have dropped 82% since a vaccine became available in 1990, hepatitis B is still the most likely to kill you if you have it; once infected, your odds of dying from it in a year are 1 in 117.6. Unlike hepatitis A, it can morph into a chronic condition, raising your risk of liver damage, cancer, and death. Hepatitis B is spread through contact with infected bodily fluid during activities such as birth, sex, and needle sticks.

Judging by the numbers, hepatitis C (HCV) doesn't sound as bad. The odds of being diagnosed in a year are just 1 in 333,300, and the odds of dying from it in a year once you have it are 1 in 450. But most people who have it develop chronic liver disease, and it's the most common reason people need new livers. There is no vaccine. Treatment takes almost a year, although an April 2009 study suggests that adding the drug telaprevir to the cocktail could cut the time in half.

The biggest risk of contracting hepatitis C comes from sharing needles. People who had blood transfusions before hepatitis screening started in the early 1990s are also at risk for B and C.

Since it's possible to have hepatitis without experiencing symptoms, many people become infected or infect others without even knowing it.

Altogether, the odds a death in the US will be due to viral hepatitis in a year are 1 in 442.8. The odds are actually worst for the 45-54 age range, at 1 in 79.31, rather than for the elderly or very young. In fact, the odds the death of a child aged 5-14 will be from viral hepatitis are just 1 in 6,602, thanks in large part to vaccines.

Vaccination, better hygiene, blood-product screening, education, and clean-needle programs have already reduced hepatitis deaths in this country to record lows. Hopefully, research into new treatments and prevention programs as well as the genetics of susceptibility and drug response will bring us further still.