Type 3c Diabetes

Type 3c diabetes develops when your pancreas experiences damage, such as from chronic pancreatitis or cystic fibrosis. People with Type 3c diabetes often also have a lack of pancreatic enzymes that are important for digestion. Type 3c diabetes is manageable with oral diabetes medications and/or insulin.


What is Type 3c diabetes?

Type 3c diabetes develops when your pancreas experiences damage that affects its ability to produce insulin. Conditions like chronic pancreatitis and cystic fibrosis can lead to pancreas damage that causes diabetes. Having your pancreas removed (pancreatectomy) also results in Type 3c diabetes.

Diabetes is a condition that happens when your blood sugar (glucose) is too high. It develops when your pancreas doesn’t make any or enough insulin (a hormone), or your body isn’t responding to the effects of insulin properly.

Your pancreas has two main functions:

  • Exocrine function: Produces enzymes that help with digestion.
  • Endocrine function: Sends out hormones (mainly insulin and glucagon) that control the amount of sugar in your bloodstream.

Pancreas damage that leads to Type 3c diabetes often also affects your pancreas’s ability to produce the enzymes that help with digestion. This condition is called exocrine pancreatic insufficiency (EPI).

Other names for Type 3c diabetes include:

  • Pancreatogenic or pancreatogenous diabetes mellitus.
  • Pancreatic diabetes.
  • Pancreoprivic diabetes.

How common is Type 3c diabetes?

Researchers estimate that Type 3c diabetes represents 1% to 9% of all diabetes cases. This range is wide because Type 3c isn’t as well-known, and people with the condition are often misdiagnosed with Type 2 diabetes.

What’s the difference between Type 1, Type 2 and Type 3c diabetes?

The main difference between these types of diabetes is what causes them.

Type 1 diabetes is an autoimmune disease in which your immune system attacks and destroys insulin-producing cells in your pancreas for unknown reasons. People with Type 1 always need insulin to manage the condition.

Type 2 diabetes develops when your body doesn’t make enough insulin and/or your body’s cells don’t respond normally to the insulin (insulin resistance). People with Type 2 diabetes may manage the condition with lifestyle changes, oral medication and/or insulin.

Type 3c diabetes results from damage to your pancreas that isn’t autoimmune. People with Type 3c often also lack the enzymes their pancreas makes for digestion. In this type, the amount of insulin your pancreas makes can vary. Some people take oral diabetes medications and others need insulin to manage the condition.


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Symptoms and Causes

What are the symptoms of Type 3c diabetes?

The symptoms of Type 3c diabetes are the same as other forms of diabetes. They include:

People with Type 3c diabetes typically also have symptoms of exocrine pancreatic insufficiency, which include:

It’s important to see a healthcare provider if you have these symptoms.

What causes Type 3c diabetes?

Type 3c diabetes develops when your pancreas experiences enough damage to affect its ability to make insulin. The damage can result from the following underlying conditions or situations:

Chronic pancreatitis

Chronic pancreatitis is long-term inflammation in your pancreas. Constant inflammation causes scarring of your pancreas tissues (fibrosis), which eventually stops it from making enzymes and hormones. About 25% to 80% of people with chronic pancreatitis develop Type 3c diabetes.

There are two main forms of chronic pancreatitis:

  • Acquired: “Acquired” means “developed after birth.” Acquired chronic pancreatitis has several possible causes. The two most common causes are gallstones and excessive alcohol use.
  • Hereditary: This form is due to genetic mutations you inherit from a biological parent. People with hereditary pancreatitis are born with genetic mutations, but they typically don’t experience the first episode of pancreatitis until late childhood.

Chronic pancreatitis is the most common cause of Type 3c diabetes — it represents about 79% of cases.

Pancreatic cancer

There’s a strong link between diabetes and pancreatic cancer, especially pancreatic ductal adenocarcinoma (the most common kind). About 50% of people diagnosed with pancreatic cancer also have diabetes.

Tumors from pancreatic cancer could potentially damage your pancreas and cause Type 3c diabetes. Researchers estimate that pancreatic cancer is the cause of about 8% of Type 3c diabetes cases.


Hemochromatosis, also called iron overload, is a condition in which your body stores too much iron.

Normally, your intestines absorb just the right amount of iron from the food you eat. But with hemochromatosis, your body absorbs extra iron and stores it in your organs, especially your heart, liver and pancreas.

Iron stores in your pancreas can cause damage, leading to Type 3c diabetes.

Hemochromatosis causes about 7% of all Type 3c diabetes cases.

Cystic fibrosis

Cystic fibrosis (CF) is a genetic (inherited) condition that causes sticky, thick mucus to build up in organs, including your lungs and pancreas.

This mucus can scar and damage your pancreas, which can prevent it from producing enough insulin, resulting in Type 3c diabetes.

Sometimes, a person with cystic fibrosis experiences insulin resistance (like in Type 2 diabetes) due to the condition. This is more likely to happen when the person is sick, on steroid medications or is pregnant.

More than 35% of adults living with CF have Type 3c diabetes. This form of diabetes is also called CF-related diabetes (CFRD).

Cystic fibrosis causes about 4% of all Type 3c diabetes cases.


A pancreatectomy is a surgery that removes part or all of your pancreas. You may need a pancreatectomy for many reasons, such as for pancreatic cancer, pancreatic cysts or severe chronic pancreatitis.

A pancreatectomy may or may not result in Type 3c diabetes. A partial pancreatectomy will leave some insulin-secreting cells behind. Sometimes they’re enough to keep your blood sugar in a healthy range.

If you’re having a total pancreatectomy, you’ll have diabetes afterward unless your surgeon can preserve some of your insulin-producing cells. Sometimes, your surgeon can transplant some of these cells into your liver.

Pancreatectomies cause about 2% of all Type 3c diabetes cases.


Diagnosis and Tests

How is Type 3c diabetes diagnosed?

It can be difficult for healthcare providers to diagnose Type 3c diabetes. This is because it isn’t a very common or well-known type of diabetes. Providers tend to misdiagnose it as Type 2 diabetes, which is a much more common form. If you have a known pancreatic condition, it’s less difficult to diagnose Type 3c.

Providers have to confirm diabetes, confirm damage to your pancreas and rule out other types of diabetes to diagnose Type 3c.

They may order the following tests to do so:

  • Fasting blood glucose test: For this test, you don’t eat or drink anything except water (fast) for at least eight hours before the test. A result of 126 mg/dL or higher typically indicates diabetes.
  • A1C: This blood test, also called HbA1C or glycated hemoglobin test, provides your average blood glucose level over the past two to three months. A result of 6.5% or higher typically indicates diabetes.
  • Imaging tests: Imaging tests, such as a computed tomography (CT) scan, can help your provider see damage to your pancreas.
  • Pancreas blood tests: These tests can check pancreas function. They measure the levels of certain digestive enzymes your pancreas produces. If the results are abnormal, they can help confirm pancreas damage.
  • Diabetes autoantibody panel: This is a blood test that checks if you have the autoantibodies that cause Type 1 diabetes. Your provider may order this test to rule out Type 1.

Management and Treatment

How is Type 3c diabetes treated?

The treatment for Type 3c diabetes varies based on the underlying cause and how much of your pancreas is damaged (or surgically removed).

People with the condition typically take an oral diabetes medication (such as metformin) and/or take synthetic insulin (with injections or an insulin pump).

Your treatment needs may change over time if your pancreas becomes more damaged. For example, an oral medication may work well to manage your blood sugar at first. But you may eventually need insulin to keep your blood sugar levels in range if your pancreas produces less and less insulin.

Other management strategies for Type 3c diabetes include:

  • Blood sugar monitoring: Monitoring your blood sugar (glucose) is key to determining how well your current treatment plan is working. It gives you information on how to manage Type 3c diabetes on a daily — and sometimes even hourly — basis. You can monitor your levels with frequent checks with a glucose meter and finger stick and/or with a continuous glucose monitor (CGM). You and your healthcare provider will determine the best blood sugar range for you.
  • Diet: Meal planning and choosing a healthy diet for you are key aspects of diabetes management in general, as food greatly impacts blood sugar. A registered dietitian can help you develop the best eating plan.
  • Exercise: Physical activity increases insulin sensitivity (and helps reduce insulin resistance), so regular exercise is an important part of management for all people with diabetes.

Diabetes is a complex condition, so its management involves several strategies. In addition, diabetes affects everyone differently, so management plans are highly individualized. You’ll likely benefit from regular visits with your healthcare team to monitor how well your treatment plan is working.

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Can I prevent Type 3c diabetes?

The only way to prevent Type 3c diabetes is to try to prevent the underlying conditions that cause it, if possible. Inherited conditions like cystic fibrosis and hereditary pancreatitis aren’t preventable. But there are steps you can take to try to prevent acquired pancreatitis, such as moderating your alcohol consumption and maintaining healthy triglyceride levels.

Outlook / Prognosis

What is the prognosis of Type 3c diabetes?

The prognosis (outlook) for Type 3c diabetes varies greatly depending on several factors, including:

  • The underlying condition that caused it.
  • How well you manage Type 3c diabetes over time and your access to diabetes care.
  • How well the underlying condition is managed.
  • Your age at diagnosis/how long you’ve had diabetes.
  • If you have other health conditions.
  • If you develop diabetes complications.

Chronic high blood sugar can cause severe complications, which are often irreversible. Several studies have shown that untreated chronic high blood sugar shortens your lifespan and worsens your quality of life.

However, it’s important to know that you can live a healthy life with diabetes. The following are key to a better prognosis:

  • Lifestyle changes.
  • Regular exercise.
  • Dietary changes.
  • Regular blood sugar monitoring.

What are the complications of Type 3c diabetes?

Blood glucose levels that remain high for too long can damage your body’s tissues and organs. This is mainly due to damage to your blood vessels and nerves, which support your body’s tissues.

Cardiovascular (heart and blood vessel) issues are the most common type of long-term diabetes complication. They include:

Other diabetes complications include:

Living With

When should I see my healthcare provider about Type 3c diabetes?

If you have a condition that affects your pancreas, such as chronic pancreatitis or hemochromatosis, talk to your healthcare provider about your risk of developing Type 3c diabetes. They’ll likely order regular tests to monitor for diabetes.

If you have Type 3c diabetes, you’ll need to see your healthcare team regularly to manage both diabetes and the underlying condition that caused it.

A note from Cleveland Clinic

It can be discouraging to learn that you’ve developed diabetes from a pancreatic condition. Managing Type 3c diabetes involves consistent care and diligence. While it’ll likely be very overwhelming at first, over time you’ll get a better grasp on managing the condition and being in tune with your body.

Be sure to see your healthcare team regularly. Managing Type 3c diabetes — and the condition that caused it — involves a team effort. You’ll want medical professionals, friends and family on your side. Don’t be afraid to reach out to them if you need help.

Medically Reviewed

Last reviewed on 05/08/2023.

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