Pancreatitis is a disease that causes the pancreas to become inflamed. It can either be acute or chronic. Acute pancreatitis occurs when the pancreas becomes suddenly inflamed, which only lasts for a few days. Symptoms can be mild, severe, and even life-threatening. With proper treatment, acute pancreatitis can be treated. But if acute pancreatitis is left untreated, this can lead to infection, bleeding, cysts, or severe tissue damage, and can also being to affect the kidneys, heart, or lungs.