Pancreatitis can happen all at once or over time. Pancreatitis that happens suddenly is called acute pancreatitis. We don't completely understand why it happens. Many people who get pancreatitis have gallstones. Alcohol abuse can also lead to this problem.
Some medicines can cause pancreatitis.
A stomach ulcer or injury is another possible cause. You may feel a bad pain in your upper abdomen. You might have this pain 12 to 24 hours after a large meal or after you drink a lot of alcohol. In very bad cases, you may go into shock. Your heartbeat may be fast.