Patients with chronic pancreatitis have vague abdominal pain, which is mostly intermittent at the beginning and turns into persistent vague pain later. The nature of abdominal pain is mostly vague, sometimes dull, drilling, or even severe pain. The pain is mostly located in the upper middle abdomen, upper left abdomen or to the right, and this vague pain is often radiating to the posterior back and both ribs. The pain is relieved when the patient is sitting, but it increases when lying down or eating. The cause of vague pain in patients with chronic pancreatitis may be related to increased pressure in the pancreatic duct due to obstruction or stenosis, and pain may also be caused by inflammation of the pancreas itself, pancreatic ischemia, pseudocysts or combined neuritis.