Managing diabetes if you have pancreatic cancer – information about type 3c diabetes

This information is for people with pancreatic cancer and type 3c diabetes. We explain the difference between type 1, type 2 and type 3c diabetes and why pancreatic cancer can cause type 3c diabetes.

Recently diagnosed diabetes can be a symptom of pancreatic cancer before someone is diagnosed. We have information about diabetes as a symptom of pancreatic cancer. And we have information on diabetes as a risk factor for pancreatic cancer.

Why does pancreatic cancer cause diabetes?

Your pancreas normally makes hormones called insulin and glucagon which keep your blood sugar at the right level. Pancreatic cancer or surgery to remove the cancer can stop your pancreas making enough of these hormones.

This can cause type 3c diabetes. This means that your blood sugar level may become too high or too low.

What are the symptoms of diabetes caused by pancreatic cancer?

The symptoms for type 3c diabetes are similar to other types of diabetes and can include:

• feeling thirsty
• weight loss
• needing to pee more often
• fatigue
• feeling lightheaded
• palpitations
• sweating
• confusion.

What are insulin and glucagon?

Insulin and glucagon are hormones made in the pancreas. Hormones are chemical messengers carried in the blood.

• Insulin reduces the amount of glucose in your blood.
• Glucagon helps to increase the amount of glucose in your blood when needed.

When you digest food and drink, carbohydrates found in starchy and sugary foods are broken down into glucose. The glucose passes into your blood causing a rise in your blood sugar level. In people who do not have diabetes, the pancreas would produce insulin to reduce the blood sugar level.

If you have type 3c diabetes, your pancreas may make less insulin and glucagon than your body needs. If your whole pancreas has been removed, your pancreas will not make any insulin or glucagon.

Who treats diabetes caused by pancreatic cancer?

Who you see to treat your diabetes may depend on services in your local area.

You may see a diabetes specialist nurse who will teach you how to monitor your blood sugar levels and help you to manage your diabetes medicine. You may also see a specialist dietitian, such as a diabetes, pancreatic or oncology dietitian, to help you manage your diabetes. Make sure you tell them that you have type 3c diabetes and pancreatic cancer. If you haven’t seen a specialist dietitian, ask your doctor or nurse to refer you to one. Your GP and hospital doctors may also help manage your diabetes.

Make sure you know who to contact about your diabetes. If you are not sure, ask your medical team.

Questions about type 3c diabetes?

It can be difficult and confusing to manage diabetes if you have pancreatic cancer. Your dietitian and diabetes nurse will help you manage your blood sugar levels and give you advice about how to live well with your diabetes. You can also speak to our specialist nurses on our free Support Line who can explain more about managing diabetes.

Updated June 2026

Review date June 2029