Being infected with HCV does not necessarily mean that liver disease will occur. What's more, it can take several years—decades, in many cases—for HCV to cause life-threatening liver disease.
Soon after HCV enters the body, it infects cells in the liver called hepatocytes. Only a small number of people (about 25 percent) actually experience symptoms of infection, such as fatigue, decreased appetite, nausea or jaundice (yellowing of the skin and eyes). However, the majority of people infected with HCV have an increase in liver enzymes—such as alanine aminotransferase (ALT)—that can be detected by a simple blood test. An increase in ALT means that some liver cells are damaged by the HCV infection.
About 15 to 25 percent of people infected with HCV are able to clear the virus from their bodies, usually within six months after becoming infected. Infants and young women are more likely to clear HCV spontaneously. However, the majority of people infected with HCV have "chronic" hepatitis C—an infection that can stay with them for life unless they are treated.
About 15 percent of people with chronic hepatitis C will maintain normal liver enzymes, even though HCV can be detected in their livers and in their blood. Although they usually don't develop progressive liver disease or experience symptoms of the infection, people with normal ALT levels are still at risk for liver damage from HCV. The remainder of people with chronic hepatitis C will go on to experience some signs and symptoms of liver disease, such as fatigue, nausea, muscle aches and abdominal discomfort.
About 5 to 20 percent of people infected with HCV will develop cirrhosis—a scarring of the liver that results from widespread fibrosis (liver cell damage). This usually occurs over a 20-to-30-year period of HCV infection. Progression to cirrhosis may be accelerated in people who are older, obese or immune-suppressed (such as people who are coinfected with HIV*). Heavy alcohol use can also speed up liver disease, notably in men who drink more than 50 grams of alcohol a day (5 drinks) and women who consume more than 30 grams of alcohol a day (3 drinks).
Although cirrhosis is not always life-threatening, it can affect the way the liver works and it does increase the risk of liver cancer. Between 1 and 5 out of 100 HCV infections will die from the consequences of chronic HCV infection, notably liver cancer or liver failure.
In other words, of every 100 people infected with the hepatitis C virus, about
75 to 85 people will develop chronic hepatitis C virus infection; of those,
60 to 70 people will go on to develop chronic liver disease,
5 to 20 people will go on to develop cirrhosis over a period of 20 to 30 years, and
1 to 5 people will die from cirrhosis or liver cancer.
Hepatitis C may increase the risk of dying early from other diseases, such as cancer and cardiovascular disease. On average, people with HCV die 15 years earlier than the general population. However, people who are cured of HCV before they reach cirrhosis, have an average life expectancy.
*HIV can worsen hepatitis C. Not only does HIV increase the risk of liver damage, it can also hasten the onset of liver damage following infection. Hepatitis C coinfection can also complicate HIV treatment, since some antiretrovirals (ARVs)—HIV medications—are less liver-friendly than others. Click here to learn more about HIV/HCV coinfection.