The period immediately following infection is called the ‘acute phase’. This lasts about six months. If the immune system does not manage to clear the virus in this time, the disease is considered to have moved into a long-term or ‘chronic phase’.
Because of the damage it can cause to the liver, HCV is classified as a liver disease. But HCV can also affect some of the body’s other systems, causing symptoms, illnesses and complications other than those associated with the liver. Until recently these other symptoms have often been seen as unconnected or unrelated. This has meant that they have been given less medical attention and, as a result, are less well researched and understood.
The effects of hepatitis C on the liver are measured by the way the liver changes as scarring develops. This progression begins with the initial inflammation of the liver caused by the virus hijacking its cells. It then starts to infect and kill off the liver cells, before the gradual scarring (fibrosis) and then the hardening of the liver tissue (cirrhosis) occurs. Throughout this progression the immune system plays a highly influential role. Although it acts to stem the spread of disease, it also accelerates the process of scarring.
Cirrhosis scars and alters the actual structure of the liver. Over time this will seriously undermine the liver’s ability to function properly. Cirrhosis is classified as being either ‘compensated’ or ‘decompensated’. If the liver can continue to carry out most of its functions despite extensive scarring then this is known as ‘compensated cirrhosis’ (meaning that the liver can compensate for the damage). If the liver’s functions are seriously affected then this is called ‘decompensated cirrhosis’. The most serious symptoms of this stage are:
- Portal Hypertension - when blood cannot properly flow through the liver and pressure rises in the portal vein leading into the liver.
- Variceal Bleeding - when the portal hypertension forces blood to re-route through veins that are too small and consequently burst, often in the oesophagus (between the throat and the stomach), causing potentially life-threatening internal bleeding.
- Oedema - when the liver stops producing enough albumin. This regulates the amount of fluid in cells. This fluid then builds up, typically in the stomach, and is known as ‘ascites’.
- Hepatic Encephalopathy - when the liver stops properly filtering poisons and toxins. These then build up in the brain leading to serious mental confusion and sometimes coma.
More information on decompensated cirrhosis can be found in End stage liver disease.
Cirrhosis also significantly increases the risk of developing liver cancer. This can develop from either compensated or decompensated cirrhosis.
Recent studies suggest that chronic infection with HCV will almost invariably result in cirrhosis. The time that this takes varies. From those who develop a chronic or long term infection (between 70-80% of those infected with HCV) around 20-30% will develop cirrhosis within 20 years. For some it may be quicker while for others it may take up to sixty years meaning they will probably die of unrelated causes first.