Diabetes and surgery

If you need surgery, it should be carefully planned to reduce your risk of problems linked to diabetes.

How surgery can affect your diabetes

Surgery is one of the main treatments for many cancers. The type of surgery you have and how it may affect you depends on the type of cancer.

Having diabetes may give you a higher risk of problems during and after surgery. For example, any surgical wounds you have may heal slower than those of someone who does not have diabetes. You are also more likely to get a wound infection if your blood sugar level is not well controlled.

Pancreatic surgery

If you have an operation to remove the whole pancreas, you will not be able to produce insulin. After surgery, you will need to start injections of insulin. You will need to regularly test your blood sugar level. A diabetes specialist team will help you with this.

If you have had part of the pancreas removed, the remaining pancreas may not be able to make enough insulin straight away. This means your blood sugar levels will not be controlled. You may need to have an insulin drip into a vein, called an infusion. You will usually only have this until the remaining pancreas recovers and starts to make insulin again. Your doctor or specialist nurse will explain this to you. The ward staff in the hospital will closely monitor your blood sugar while you recover. If you do not already have diabetes, there is a higher risk of developing it in the future after this operation.

Planning your operation

To help prevent problems, your operation should be carefully planned. You will be closely monitored during and after the operation. Most operations for cancer are planned. This means you should have time to prepare. Very occasionally you may need to have an emergency operation. It is more difficult to plan for this, but you will still be closely monitored.

You can reduce the risk of any problems by keeping your diabetes as well-controlled as possible in the weeks before your operation. Your diabetes team can help you with this.

Before your operation, you should have an appointment at a pre-surgery assessment clinic. This is to talk about the plan for your care. Tell the doctors that you have diabetes and about any problems you have. Having surgery can be more risky if you have problems because of diabetes. This includes problems with your heart, eyes or kidneys.

If you have lost any feeling in your feet, your doctor may arrange tests to check your health before your operation. They will explain the tests and why you need them.


Your healthcare team

Talk to your diabetes team about your operation. They can talk to your surgeon and make sure you get the best advice to help you prepare. This advice will depend on how you manage your diabetes:

  • If you take tablets, you may be asked to stop them for a short time before and after the operation.
  • If you use insulin, you may need to change the dose. You should not stop taking insulin.

Ask your doctors or specialist nurse for some written information so you know exactly what you need to do and when.

Before your operation, you will meet the doctor who puts you to sleep and makes sure you are safe during the operation (the anaesthetist). They will tell you how they will care for you and control your blood sugar during surgery.

The day of your operation

You will normally be admitted to hospital on the morning of your operation. Sometimes you may be asked to come in the day before, so that the nurses can monitor your blood sugar level. You may have a drip (infusion) of sugar and insulin to help keep your blood sugar level well-controlled.

Your doctor will ask you not to eat or drink anything for a few hours before the operation. This is to help reduce the risk of you being sick.

Where possible, you should be the first person on the operating list for that morning or afternoon. This will help reduce the amount of time you cannot eat. The hospital team will plan the best way to manage your diabetes when you are not eating. This will depend on how long you cannot eat:

  • If you miss one meal, you should be able to control your diabetes by adjusting your normal routine.
  • If you miss 2 or more meals, you may need a drip of sugar and insulin for a short time. How much insulin you have will depend on your blood sugar level. Your nurses will regularly check this.

Having an operation can increase the risk of a blood clot in the leg. Compression stockings (also known as anti-embolic stockings) help to reduce this risk. You might be asked to wear compression stockings during your operation and for a while afterwards. Tell your doctor or nurses if you have any problems with feeling or circulation in your feet. If you do, you should not wear compression stockings.

After your operation

You should start to manage your diabetes again as soon as possible after your operation. The hospital team will help you do this. You may have trouble controlling your blood sugar at first. This may be because you are:

  • not allowed to eat normally
  • being sick
  • in pain
  • less active than normal
  • stressed.

The nurses on the ward will check your blood sugar level regularly. You will not have to manage your diabetes yourself until you are well enough.

  • Eating and drinking

    You will have the drip of sugar and insulin until you can start eating and drinking again. Some people will be able to eat soon after their operation. For others, it may take longer. This will depend on the type of operation you have had. Your doctors will try to get you eating normally as soon as possible. They will tell you how soon you can start eating and drinking again. They will also tell you when you should start taking your usual diabetes medicines.

  • Risk of developing bedsores

    If you are in bed for a long time, you are at risk of developing bedsores (pressure sores). It is important that you move around the bed and change your position. It is even more important if you have less feeling in your hands and feet. This is because you may not feel if you are developing a sore. You should try to get up soon after your operation. The ward staff will help you with this. Moving around will also help your blood sugar level return to normal.

  • Your wound

    Any stitches, clips or staples in your wound are usually taken out 7 to 10 days after the operation. The wound may take longer to heal if your blood sugar level is not well-controlled. The practice nurse at your GP surgery can remove any stitches. If you cannot leave home, a district nurse can visit you. The nurses on the ward can arrange this before you go home.

  • Risk of infection

    If your diabetes is not well-controlled, you are more at risk of developing an infection. Let your nurse or doctor know straight away if your wound becomes hot, painful or starts to bleed or leak any fluids. You should also tell them if this happens when you go home.

Your cancer doctor or specialist nurse will tell you when you can go home. You may have to stay in hospital longer than someone who does not have diabetes.

This information was produced in partnership with Diabetes UK.
In partnership with Diabetes UK. Know diabetes. Fight diabetes.
Image: Diabetes UK

Date reviewed

Reviewed: 31 January 2020
Next review: 31 January 2023

This content is currently being reviewed. New information will be coming soon.

Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.