Acute pancreatitis is poorly understood and there is much about the condition that remains unknown. For example, it is still unclear what triggers the inflammation inside the pancreas or why some people have the mild form of the condition and others have the severe form.
Trypsin
One theory is that acute pancreatitis is caused when something goes wrong with a chemical called trypsin. Trypsin is an enzyme that is produced by the pancreas and is used to break down the proteins in food to aid digestion.
When trypsin is produced by the pancreas, it remains in an ‘inactive’ state and has no digestive properties. It is not until it is moved out of the pancreas and into the intestines that it becomes active and is able to start breaking down proteins.
The theory suggests that something causes trypsin to become active while it is still in the pancreas, making it break down its own cells. In other words, the pancreas starts trying to digest itself, which causes it to become irritated and inflamed.
Alcohol consumption
It is not fully understood how alcohol causes the pancreas to become inflamed. One theory is that the ethanol molecules in alcohol interfere with the normal workings of the cells of the pancreas, causing them to activate trypsin prematurely.
Whatever the cause, there is a clear link between alcohol use and acute pancreatitis, and the more alcohol you drink, the higher your risk.
A very large study found that people who regularly drank more than 35 units of alcohol a week were four times more likely to develop acute pancreatitis than people who never drank alcohol (35 units is equivalent to drinking around 16 cans of strong lager or four bottles of wine a week).
Binge drinking, which is drinking a lot of alcohol in a short period of time, is thought to increase your risk of developing acute pancreatitis.
Gallstones
Gallstones are hard pieces of stone-like material that can form if your bile (digestive juices) has too much cholesterol in it. Sometimes a gallstone can move out of the gallbladder and block the openings (ducts) to the pancreas.
It is thought that the blockage causes a disruption in the chemical reactions that occur within the pancreas. This could lead to the activation of trypsin inside the pancreas and trigger the process of inflammation.
See the Health A-Z topic about gallstones for more information.
Other causes
Other, less common, causes of acute pancreatitis include:
- accidental damage to the pancreas that occurs during a type of surgery known as endoscopic retrograde cholangiopancreatography (ERCP), which is used to remove gallstones or examine the pancreas or surrounding tissue
- an unexpected side effect of certain types of medication in a small number of people, such as some type of antibiotics or chemotherapy medication
- a viral infection, such as mumps or measles
Risk factors for severe pancreatitis
Little is known about why some people develop the severe form of acute pancreatitis. Several researchers have studied case files to see whether they could spot factors that make a person more likely to develop severe acute pancreatitis.
The results of this research strongly suggest that the following risk factors increase your risk of developing severe acute pancreatitis:
- being 70 years of age or over
- being obese - a person is considered obese if they have a body mass index (BMI) of 30 or above
- having two or more alcoholic drinks a day
- smoking
Researchers have also discovered that people with a specific genetic mutation, known as the MCP-1 mutation, are eight times more likely to develop severe acute pancreatitis than the population at large. A genetic mutation is where the instructions that are found in all living cells become scrambled, resulting in a genetic disorder or a change in characteristics.
