Hepatitis C is an infectious liver disease that occurs in at least 1 percent of the U.S. population, according to the Centers for Disease Control and Prevention. The hepatitis C virus attacks the liver, causing inflammation and scarring. Progressing in stages over the course of several decades, chronic hepatitis C is characterized by gradual and ongoing damage to the liver. In some people, the stages of the disease continue to progress until the liver can no longer function properly.
Acute Hepatitis C
The first stage of hepatitis C is known as the acute stage. During this time, the virus attacks the liver, multiplying and spreading within the liver. As the immune system attempts to fight the virus, the liver becomes inflamed. Only 20 to 30 percent of people experience symptoms with acute hepatitis C, notes CDC. The possibilities include flulike symptoms, yellowing of the skin or whites of the eyes, and pale stools.
Approximately 15 to 25 percent of people with acute hepatitis C clear the virus within 6 months without any permanent damage to the liver, according to CDC. For this reason, treatment is rarely recommended at this stage of the illness. Women, younger people and those with a strong immune response are most likely to clear the virus on their own. Among people who do not clear the virus, hepatitis C becomes chronic and causes ongoing liver inflammation.
Chronic Hepatitis C
During the chronic stage of hepatitis C, viruses continue to multiply and attack liver cells as the immune system battles the infection. Infected liver cells die and new ones are generated to take their place as the liver tries to heal itself. However, the ongoing inflammation associated with the fight between the virus and the immune system leads to liver scarring, which slowly builds up over decades if hepatitis C is left untreated. This liver scarring, known as fibrosis, is a hallmark of chronic hepatitis C. Factors that tend to increase the rate of liver scarring include:
-- Male sex.
-- Infection after age 40.
-- Drinking alcohol.
-- Prediabetes and diabetes.
-- Coinfection with HIV or the hepatitis B virus.
People with chronic hepatitis C often experience no signs or symptoms despite ongoing liver inflammation and scarring. Successful treatment with direct-acting antivirals halts these harmful processes, and some liver damage might be reversible if not too extensive.
Longstanding hepatitis C can advance to cirrhosis, meaning the liver scarring is so severe that the organ's basic structure is distorted. Hepatitis C advances to cirrhosis in approximately 5 to 20 percent of people with the disease, according to CDC. With early-stage cirrhosis, called compensated cirrhosis, the liver is still able to function, and the disease generally causes no symptoms.
Immediate treatment with direct-acting antiviral therapy is recommended for people with early cirrhosis caused by hepatitis C, according to guidelines from the American Association for Liver Diseases, Infectious Diseases Society of America and International Antiviral Society - USA. Successful treatment can slow, stop and sometimes partially heal existing liver damage. Without treatment, scar tissue can continue to build up and lead to advanced cirrhosis with liver failure.
Left untreated, early-stage cirrhosis can progress to advanced cirrhosis with accompanying liver failure. With advanced-stage cirrhosis, much of the liver is supplanted by scar tissue. With an inadequate number of healthy liver cells, the liver can no longer perform its many vital functions. Additionally, the buildup of scar tissue obstructs blood flow through the liver. This condition, called portal hypertension, causes a backup of blood and high pressure in the circulation that flows into the liver. The combination of poor liver function and portal hypertension causes a variety of symptoms, which might include:
-- Swelling of the abdomen due to fluid buildup.
-- Weight loss and decreased muscle tissue in the arms and legs.
-- Yellowing of the skin and whites of the eyes.
-- Easy bruising and bleeding.
-- Vomiting blood or passing bloody stools.
-- Confusion, extreme drowsiness or coma.
A liver transplant is often needed to treat people with advanced-stage cirrhosis due to hepatitis C.
Though this is not a separate stage of hepatitis C, people who develop cirrhosis because of the infection are at increased risk of developing liver cancer. Each year, people with hepatitis C-induced cirrhosis face a 1 to 4 percent chance of developing liver cancer, according to an article published in "Hepatology" in November 2002. The mechanisms by which hepatitis C infection causes liver cells to become cancerous are complex, but they relate to ongoing inflammation and direct interactions between the virus and liver cells.
People with advanced fibrosis or cirrhosis continue to be at increased risk for liver cancer even after successful treatment and clearance of the hepatitis C virus. For this reason, the American Association for Liver Diseases, Infectious Diseases Society of America and International Antiviral Society - USA guidelines recommend twice yearly liver ultrasound testing to monitor for possible development of liver cancer.
Many people with hepatitis C are unaware they have the disease, so testing is important for early diagnosis and treatment. Hepatitis C can only be diagnosed through a blood test. CDC recommends hepatitis C screening for:
-- Anyone born between 1945 and 1965.
-- Current and former intravenous drug users.
-- People who received an organ transplant or blood transfusion prior to 1992.
-- All people with HIV.
-- People who have been on long-term dialysis for kidney failure.
Talk with your doctor if you are unsure whether you should be tested for hepatitis C. Contact your doctor immediately if you have any signs or symptoms of liver failure. Seek emergency medical care if you vomit blood, pass bloody or black stools or experience sudden mental changes.
Medical advisor: Tina St. John, M.D.