Inflammation of the liver (hepatitis) includes a very broad group of diseases with different causes, course and prognosis. It is appropriate to devote this issue a simple article.
First, it is advisable to divide liver inflammation into infectious and non-infectious and into acute and chronic.
Acute inflammation occurs suddenly and it is usually accompanied with unpleasant symptoms such as liver enlargement, right upper quadrant abdominal pain, jaundice, fatigue, loss of appetite, etc.). Acute inflammation may either heal spontaneously or progress into chronic inflammation or even into acute liver failure.
Chronic inflammation is long-term, it is relatively asymptomatic and it may be diagnosed incidentally. The main danger is gradual progression into liver cirrhosis, with all possible complications (see the text related to cirrhosis).
There are many factors causing inflammation of the liver tissue, I will mention only the best-known and clinically important.
Infectious hepatitis can be acute or chronic. They may be caused by bacteria, viruses or parasites. Perhaps the most significant is viral hepatitis A-E and liver damage occurring in viral infectious mononucleosis. Liver affection occurs in parasitic infection by echinococcus, which forms liver cysts. Bacterial infections of liver tend to be bordered forming abscesses.
Drugs and toxic substances
Many substances can cause acute liver inflammation that can turn chronic. For example, such harmful substance is amiodarone (used to treat heart rhythm disorders), paracetamol, hormonal contraception and many more. Liver may be severely damaged by some toxins, fro example by toxic substances in a mushroom known as “death cap”.
Alcohol should be mentioned separately. Excessive intake of alcohol can cause acute inflammation of the liver (alcoholic hepatitis), while long-term alcoholism is rather associated with chronic inflammation, which results in cirrhosis.
Congenital and metabolic diseases
These inherited genetically determined diseases include particularly hemochromatosis (inflammation caused by deposition of iron), Wilson's disease (inflammation induced by deposition of copper) and alpha-1-antitrypsin deficiency.
In this group of diseases, the inflammation is caused by our own immune system. These pathological conditions include for autoimmune hepatitis, primary biliary cirrhosis and primary sclerosing cholangitis.
Abnormal flow of bile
Virtually any condition which leads to prolonged obstruction of biliary tract can lead to chronic inflammation of the liver tissue. All common causes can be found in text dedicated to jaundice.
The abbreviation NASH means non-alcoholic steatohepatitis. It is quite likely an underestimated liver disease that is caused by excessive storage of fat within the liver tissue. If NASH develops, there is 10-20% probability that the condition is going to progress into cirrhosis.
Ischemia means lack of oxygen. Liver needs a continuous supply of oxygen due to intensive chemical and metabolic activity. Lack of oxygen in liver is commonly present during circulatory shock with decreased blood pressure. Another possible cause is acute obstruction by hepatic artery by a blood clot.
The diagnosis should begin with medical history. The doctor should have information about patient’s previously known diseases, present medications, family history and one’s attitude to alcohol. Physical examination should focus on abdomen and its upper right quadrant where the liver is located. Blood tests are very important for evaluation of liver tests and the level of bilirubin. Abdominal ultrasound is imaging method of the first choice as it can find the majority of pathologies of liver and biliary tract. When the diagnosis is uncertain, it is possible to perform liver biopsy to obtain a sample of liver tissue for histological examination.