Hepatitis has many causes and types. Most of them cause either acute or chronic hepatitis and depends on how long they are affecting the liver. Healthcare providers classify common causes into types of hepatitis. 
 

Viral hepatitis: 

Viral hepatitis is caused by viruses that infect and damage the liver cells, which leads to inflammation which is a response from your immune system. Viral infections that cause hepatitis include: 
 

• Hepatitis A: Hepatitis A is an acute infection causing acute hepatitis. However, it can last several months, and occasionally it is severe enough to cause acute liver failure. It is caused by Hepatitis A virus (HAV). Hepatitis A spreads through contaminated water, food or close contact with infected person.  
   

• Hepatitis B: Hepatitis B begins as an acute infection, but a small percentage of people develop a chronic infection and chronic hepatitis. It is caused by Hepatitis B virus (HBV). Hepatitis B spreads through contact with infected blood or bodily fluids, such as semen or vaginal fluids.  
   

• Hepatitis C: Hepatitis C begins as an acute infection. But the majority of people who get it develop a chronic infection. It is one of the most common causes of chronic hepatitis. It is caused by Hepatitis C virus (HCV). Hepatitis C spreads through contact with infected blood, typically through sharing needles or syringes used for drugs or medications, or from a mother to her baby during birth.  

• Hepatitis D: Hepatitis D (delta virus) infects people who already have hepatitis B. It can also cause chronic hepatitis. If someone gets both, it can be especially stressful for the liver. It is caused by the Hepatitis D virus (HDV) and requires Hepatitis B to occur (co-infection). Hepatitis D spreads through contact with infected blood or bodily fluids.  

• Hepatitis E: Hepatitis E is most prevalent in Asia and uncommon in other parts of the world. It causes acute infection with acute hepatitis. It is caused by Hepatitis E virus (HEV). Hepatitis spreads through contaminated food or water, similar to hepatitis A.  
  
  

Toxic hepatitis 

Toxins in the bloodstream can cause toxic hepatitis, especially in higher doses and when the liver is already stressed for another reason. The liver filters toxins from the blood every day, but if the toxic load gets too heavy, these toxins can slow it down or even damage its cells. The damage can be acute or chronic, depending on how severe it is and how often or how long you are exposed. Causes include: 

• Industrial chemicals, including vinyl chloride, carbon tetrachloride and certain pesticides and herbicides. 

• Over the counter (OTC) medications, especially high doses of nonsteroidal anti-inflammatory drugs.  

• Prescription drugs, including statins, certain antibiotics and anti-seizure medications. 

• Some herbs and supplements in large or frequent doses. 
   

Alcohol-induced hepatitis 

Alcohol-induced hepatitis can be chronic or acute. One can get acute hepatitis after a short drinking binge or chronic hepatitis from chronic, heavy alcohol use. Alcohol is always toxic to your liver, but most people can tolerate a certain amount. However, how much is too much varies. While most people develop hepatitis from heavy drinking, some people are more sensitive to alcohol than others. 

Metabolic dysfunction-associated steatohepatitis 

Steatohepatitis means hepatitis from fat. It is an advanced stage of fatty liver disease. That means your liver has begun storing extra fat in its tissues. Alcohol use is one common cause of fat storage in your liver. When it is not alcohol-related, it is called metabolic dysfunction-associated steatotic liver disease. When this excess fat builds up enough, it can cause metabolic dysfunction-associated steatohepatitis. This is related to: 

• Hyperlipidaemia (excess fats in your blood). 

• Overweight and obesity (BMI of 25 or higher). 

• High blood sugar, insulin resistance and Type 2 diabetes. 

• High blood pressure and cardiovascular disease. 
  
  

Autoimmune hepatitis 

Some people develop chronic hepatitis as an autoimmune disease. That means their immune systems mistakenly attack their own liver tissues. Autoimmune diseases often develop for no apparent reason. While autoimmune hepatitis causes liver inflammation directly, other autoimmune diseases can affect the bile ducts that run through your liver (primary biliary cholangitis or primary sclerosing cholangitis). 

Other causes 

Other possible causes of hepatitis include: 

• Cholestasis. Cholestasis means that bile flow has stalled within the biliary tract. The liver is part of the biliary system: It makes and delivers bile through the bile ducts. When bile flow stalls, bile can back up into the liver and cause hepatitis. This can happen suddenly (acute), due to a bile duct obstruction, or gradually (chronic), due to a chronic disease or condition. 

• Inherited metabolic disorders. Rare genetic disorders that affect the metabolism can also affect the liver. For example, Wilson disease and hemochromatosis are both conditions that cause toxic levels of metals to build up in the liver. Gaucher disease and glycogen storage disease (GSD) cause metabolic waste products to build up in the body, which the liver filters. 
  
  
• Ischemia: Ischemia is a sudden or gradual loss of blood flow to one of the organs. It can cause acute or chronic inflammation anywhere in the body. Common causes include sudden vasoconstriction, occlusions such as blood clots and arterial diseases that narrow your arteries. Sometimes, ischemia is a response to shock from a severe infection or organ failure.