The pancreas has two major jobs: it produces enzymes that break down the food you eat, and it releases hormones that control your blood sugar. It sits deep in your abdomen, partly sandwiched between your stomach and spine, with its other end nestled into the curve of the small intestine. Despite being relatively small, it plays a central role in both digestion and metabolism.
Where the Pancreas Sits in Your Body
The pancreas stretches horizontally across the back of the abdomen. Its widest section, the head, sits on the right side of the body, tucked into the C-shaped curve of the duodenum (the first part of the small intestine). A thin neck connects the head to the body, which is the middle portion. The tail tapers to a narrow tip on the left side, near the spleen. This positioning matters because it places the pancreas right where digested food exits the stomach, allowing it to deliver enzymes exactly where they’re needed.
Digestive Enzymes: The Exocrine Role
About 95% of the pancreas is devoted to digestion. Johns Hopkins Medicine describes it as the enzyme “powerhouse” of digestion, and for good reason. It produces three main types of enzymes, each targeting a different nutrient in your food:
- Amylase breaks down complex carbohydrates into simpler sugars your body can absorb. Your mouth also makes amylase, but the pancreas produces it in much larger quantities.
- Lipase breaks down fats into fatty acids and glycerol. Without enough lipase, dietary fat passes through undigested, which causes greasy stools and poor absorption of fat-soluble vitamins.
- Protease breaks down proteins into amino acids, the building blocks your body uses for muscle, immune function, and countless other processes.
These enzymes don’t release randomly. When partially digested food enters the small intestine, specialized cells lining the duodenum detect the presence of fats and proteins. Those cells release a hormone called cholecystokinin into the bloodstream, which signals the pancreas to contract and push enzymes into the digestive tract. This on-demand system means the pancreas ramps up production when you eat and stays relatively quiet between meals.
Neutralizing Stomach Acid
The pancreas has a less well-known digestive job: it produces an alkaline fluid rich in bicarbonate. Your stomach digests food in a highly acidic environment, and when that acidic mixture enters the small intestine, enzymes can’t work efficiently. Pancreatic duct cells secrete fluid containing concentrations of bicarbonate as high as 140 millimoles per liter, raising the pH of the intestinal contents to around 8.0. This neutralization protects the lining of the small intestine from acid damage and creates the right chemical environment for digestive enzymes to function.
Blood Sugar Regulation: The Endocrine Role
Scattered throughout the pancreas are small clusters of hormone-producing cells called the islets of Langerhans. They make up only about 5% of the organ’s tissue, but their role is critical. These islets contain several distinct cell types, each producing a different hormone.
The two most important are beta cells and alpha cells. Beta cells, which make up roughly 60% of each islet, produce insulin. When your blood sugar rises after a meal, beta cells detect the increase and release insulin, which tells your muscles, liver, and fat tissue to absorb glucose from the blood. A healthy fasting blood sugar level is below 100 mg/dL, and insulin is the primary hormone responsible for keeping it in that range.
Alpha cells make up about 30% of each islet and produce glucagon, which does the opposite of insulin. When blood sugar drops between meals or during exercise, alpha cells release glucagon, signaling the liver to convert stored glycogen back into glucose and release it into the bloodstream. This push-and-pull between insulin and glucagon keeps your blood sugar remarkably stable throughout the day.
The Pancreas Has a Built-In Braking System
The remaining 10% of islet cells produce lesser-known hormones that fine-tune the system. Delta cells produce somatostatin, which acts as a brake on the other pancreatic hormones. When blood sugar drops too low, somatostatin suppresses further insulin release to prevent levels from falling dangerously. When blood sugar is high, it can suppress glucagon instead. Somatostatin also slows the release of digestive enzymes and gastric acid when they’re no longer needed, essentially telling the system to stop producing what it has already made enough of.
Two other cell types round out the picture. PP cells (sometimes called F cells) release pancreatic polypeptide, which helps inhibit glucagon when glucose levels are low. Epsilon cells produce ghrelin, a hormone better known for its role in hunger signaling, which also acts as an inhibitor of insulin secretion. Together, these minor hormones create a layered feedback system that prevents the pancreas from overshooting in either direction.
What Happens When the Pancreas Doesn’t Work Properly
Because the pancreas handles both digestion and blood sugar control, problems with the organ can show up in very different ways depending on which function is affected.
When the endocrine system fails, the result is typically diabetes. In type 1 diabetes, the immune system destroys beta cells, eliminating insulin production. In type 2 diabetes, beta cells still produce insulin, but the body stops responding to it effectively, and over time the cells may burn out. Either way, blood sugar rises above that normal fasting threshold of 100 mg/dL and stays elevated.
When the exocrine system is compromised, usually from chronic pancreatitis or after pancreatic surgery, the result is called exocrine pancreatic insufficiency. Without adequate enzyme production, your body struggles to break down and absorb nutrients from food. Common signs include bloating, gas, diarrhea, and unintentional weight loss. Doctors can check pancreatic function with a blood test measuring lipase levels; a normal range is generally 0 to 160 units per liter.
Pancreatitis, or inflammation of the pancreas, can be acute (a sudden episode, often caused by gallstones or heavy alcohol use) or chronic (long-term damage that gradually reduces function). Acute pancreatitis causes severe upper abdominal pain that often radiates to the back, while chronic pancreatitis leads to a slow decline in both digestive and hormonal output over months or years.