What causes fatigue?

This page has information about some of the causes of fatigue for people with pancreatic cancer, and how to manage these.

What's in the 'Fatigue and pancreatic cancer' section?

Fatigue may be caused by the pancreatic cancer or the symptoms of the cancer, or it may be a side effect of treatment. Fatigue is a very common symptom of cancer and is often called cancer-related fatigue.

This page has information about the causes of fatigue. There is information on other ways to deal with fatigue in the next section.

The cancer

The cancer itself can cause fatigue, although we don’t fully understand how or why this happens. People may have fatigue when they are diagnosed, even before they start treatment. Other symptoms caused by pancreatic cancer, such as problems digesting food, can also cause fatigue.

It is important that you tell your doctor or nurse about any fatigue. They should check for possible causes, and work out the best ways to deal with it. For example, treating other symptoms may help the fatigue.

Problems with digestion and diet

The pancreas makes enzymes that help to break down your food so your body can absorb nutrients and energy from it. Pancreatic cancer can affect this process, which means that your food isn’t properly digested and you don’t get the energy you need from it. Not getting enough energy from your food can cause fatigue.

Problems with digestion can also cause loss of appetite, tummy discomfort, diarrhoea and sickness. These can all mean that you may eat less, and so get less energy from your food. Fatigue may also mean that you feel less like eating.

What can help?

There are ways to manage problems with eating and digestion. Pancreatic enzyme replacement therapy (PERT) replaces the enzymes that your pancreas would normally make. The replacement enzymes help to break down food so that your body can absorb the nutrients and energy from it. They can can make a big difference to how you feel.

A dietitian is a professional who provides advice about diet and nutrition. They can support you to make changes to your diet to make sure you get enough nutrients and energy from your food. This is important as eating well and keeping your weight stable may improve how you feel and help you cope better with the cancer and treatment. This can also help with managing fatigue. The dietitian should check whether you need pancreatic enzymes.

Some people may need to take vitamin and mineral supplements or nutritional supplements, to make sure they get all the nutrients they need. Speak to your dietitian, nurse or doctor about whether these might help.

You can speak to our specialist nurses on our free Support Line with any questions about diet.

"Getting my appetite back, some mild exercise to help to restore some normality, and weight gain all helped with the fatigue."

Problems with blood sugar levels (diabetes)

The pancreas produces hormones including insulin and glucagon which control the amount of sugar in your blood. If you have pancreatic cancer, your pancreas may not produce enough of these hormones. This may mean that your blood sugar level is not properly controlled, which can cause diabetes.

If your blood sugar level is too high you may feel tired, lethargic and confused.

What can help?

Diabetes can be managed with tablets or injections. Pancreatic cancer can make it more difficult to control diabetes – but your dietitian or nurse can help with this.

It is important that you eat well to maintain your weight, and that your diabetes is managed around this. Don’t try to reduce how much you eat to manage your diabetes. Read more about managing diabetes if you have pancreatic cancer.

If you have any questions about managing your diabetes, speak to your dietitian or nurse. You can also speak to our specialist nurses on our Support Line.


Pancreatic cancer can cause pain for some people. Pain may be linked to fatigue, although we need more research into this.

Having pain can be exhausting, and it may cause problems sleeping. It may also mean that you can’t do much physical activity, which can help with fatigue. Your fatigue may be worse when you have more pain and you may feel less tired when you have less pain.

What can help?

There are treatments for pancreatic cancer pain. Tell your doctor, nurse or GP about any pain as soon as you can. The earlier you get treatment, the better the chance of getting the pain under control.

A professional called an occupational therapist can also help with managing pain by giving advice about how best to sit or lie down, or providing an appropriate bed or chair. A comfortable chair with back support may also help you to rest properly and save energy.

Some treatments for pain can cause tiredness. Opioid painkillers can make you feel sleepy, especially when you first start taking them or when the dose is changed. Drinking alcohol can make this worse.The sleepiness should improve as your body gets used to the painkillers.

Speak to your doctor or nurse about treatments for pain, and any side effects that might affect your fatigue. You can also speak to our specialist nurses.

Being sick

Pancreatic cancer can make you feel and be sick (nausea and vomiting). Some treatments, such as chemotherapy and radiotherapy, can also make you sick.

Being sick can be exhausting. It may also mean that you don’t absorb all the nutrients and energy you need from your food, making you tired. Being sick can also make you dehydrated, which happens when the body loses more water than it takes in. Dehydration can make fatigue worse.

What can help?

Tell your doctor or nurse if you feel or are sick. There are ways to treat sickness, such as anti-sickness medicines. Some of these can make you sleepy, so tell your doctor or nurse if you also have fatigue.

If you are being sick a lot (for half a day or more or every few days) and it doesn’t improve, contact your GP or medical team for advice. If you are on chemotherapy, being sick a lot can be a sign of an infection. The medical team should have given you a phone number to call for urgent advice, especially if your temperature is above 37.5°C.

"She couldn’t do the everyday things she used to like getting out the house as much, the sickness made her constantly exhausted. Only rest and being able to eat what she could helped."

Questions about symptoms and fatigue?

Speak to your doctor or nurse about any symptoms or side effects that might cause fatigue, such as problems with diet and digestion, pain or feeling sick.

You can also speak to our specialist nurses with any questions about your fatigue.

Specialist nurse Support Line
PCUK Specialist Nurse, Dianne Dobson, taking a Support Line call on the phone

Advanced pancreatic cancer

Advanced pancreatic cancer is cancer that has spread to other parts of the body, such as the liver and lungs. If you have advanced cancer, you may find that the fatigue gets worse over time, and that it has more of an effect on your daily life. This is normal, but it can be upsetting for you and your family.

What can help?

Speak to your doctor or nurse if your fatigue is getting worse, or having more of an impact on you. They may be able to change the way they are managing your symptoms or change your medicines to help the fatigue.

You may find that you are less able to do some of the things here to manage your fatigue. For example, you might not be able to do as much physical activity. Other things, such as planning your time to save energy, or relaxing complementary therapies may still help.

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Some treatments for the cancer and symptoms can also cause fatigue.


Fatigue is a common side effect of chemotherapy. Some people find that the fatigue starts a few hours to a few days after having chemotherapy, and improves after a few days. It can take several months after treatment for the fatigue to fully improve.

What can help?

See how the chemotherapy affects you, and work out how much activity you can manage. For example, you may want to do very little on the days after chemotherapy when you are more likely to have fatigue. And you could plan activities on the days when the fatigue is likely to have improved.

Speak to your doctor or nurse if you are having chemotherapy and have fatigue. They may be able to change the dose of your chemotherapy to reduce the fatigue.

"My dad has chemo on Fridays. Come Tuesday and Wednesday, he can't get out of bed. The two days are an absolute write off. After these two days though, he regains some energy and has 5 good days!"

Surgery to remove the cancer

Surgery to remove pancreatic cancer, such as the Whipple’s operation, is major surgery. It is normal to feel tired and weak afterwards, and it can take several months, or sometimes longer, to recover. Some people find that they still sometimes get fatigue a year or more after surgery.

It will take time to get back to eating normally after surgery. Removing all or part of the pancreas may affect how well you can digest food, and you may need pancreatic enzymes to help with this. Having part of your pancreas removed may also cause diabetes. Eating less, problems with digestion and diabetes can all cause fatigue.

What can help?

Treating any effects of the surgery, such as problems digesting food and diabetes, may help.

Try to gradually get back to daily activities such as walking and light household tasks. You may find that physical activity helps. Slowly build up how much you do, but don’t overdo it. Listen to your body and rest when you need to.

You may find it helpful to try to plan your time to manage your fatigue.

"It was hard to find the energy to do anything after surgery. I’m slowly improving but still regularly get times when I need to stop and sleep for an hour or so in the day."

Bypass surgery

Pancreatic cancer can block the bile duct. This is a tube that carries fluid called bile from the liver to the duodenum, which is the first part of the small intestine. This causes jaundice (yellow eyes and skin, and itching). The cancer can also block the duodenum, causing sickness. If surgery to remove the cancer isn’t possible, some people may have surgery to bypass the blockage and treat the symptoms.

Bypass surgery is a big operation, and it may take some time to recover. You may feel tired and weak at first.

What can help?

Slowly increase how much you do, and rest when you need to. Gentle physical activity, such as walking, may help you recover from the surgery. Your medical team can give you advice about the best type of exercise to do.

It may also take time for your appetite to improve after having bypass surgery. Try starting with small amounts of food often, and then gradually have bigger meals.

You may find it helps to plan your time for when you have more energy.


Some people with pancreatic cancer may have radiotherapy, which is sometimes combined with chemotherapy (chemoradiotherapy). Fatigue is a common side effect of radiotherapy. You may need to travel to hospital every day for treatment which can make fatigue worse.

Fatigue can last for several weeks or months after treatment finishes.

What can help?

If you have fatigue during or after radiotherapy, talk to your nurse or medical team about how to manage it.

See how the radiotherapy affects you, and work out how much activity you can manage. Read more about planning your time to manage fatigue.


Some medicines can make you feel sleepy or drowsy. For example, opioid painkillers like morphine, and some anti-sickness medicines such as metoclopramide and lorazepam can cause drowsiness.

What can help?

Speak to your doctor or nurse if you think your medicine may be making you tired or sleepy. They may be able to change it to a different drug, change the dose, or suggest you take it at a different time. Don’t stop taking your medicine without speaking to your doctor or nurse.

If your medicine makes you sleepy, this may affect your ability to drive. Read more about driving if you feel tired.

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"It took several weeks to realise that it was the metoclopramide that made me so fatigued after chemotherapy, not the chemotherapy itself."


Anaemia is a low level of red blood cells or haemoglobin. Haemoglobin is the part of the red blood cell that carries oxygen around the body. Anaemia can be caused by chemotherapy. It can make you feel tired, dizzy, short of breath and have problems concentrating.

What can help?

You will have regular blood tests during chemotherapy to check your blood cell levels – this is called a full blood count. If the level of red blood cells or haemoglobin is very low you may need a blood transfusion. A transfusion involves giving blood through a drip. This should quickly increase the red blood cell levels and treat the anaemia, which should help the fatigue.

Anxiety and depression

When you have cancer it’s natural to feel worried, anxious or stressed. But these feelings can become overwhelming. Anxiety and depression can be common in people with pancreatic cancer. And depression can be linked to fatigue in people with cancer. Depression and anxiety may cause fatigue, and fatigue can be a symptom of depression.

What can help?

If you have any of these symptoms, or are feeling down or low, speak to your doctor or nurse. Getting depression diagnosed and treated may help you feel more in control and help to reduce your fatigue.

Talk to your medical team about anything that’s worrying you. They can help with any physical things such as symptoms and side effects. They can also help with other things – for example, they can tell you how to get advice about financial issues. Dealing with problems like these may reduce stress and anxiety. There is also other support available to help you cope with pancreatic cancer.

There are ways to deal with depression and anxiety.

Psychological therapies

Psychological therapies can help with anxiety and depression by talking through your feelings and finding ways to deal with them. They include cognitive behavioural therapy (CBT) and counselling. Your GP or medical team can refer you to psychological therapies, or you can contact your local service yourself. Waiting times for psychological therapies can vary, so you might want to ask about them early on if you have anxiety or depression.

CBT is a talking therapy that can help you deal with worries, anxiety and depression. Read more about CBT.

Counselling involves talking to a trained counsellor about your feelings, and finding ways to deal with your emotions. Your doctor or nurse may be able to refer you to a counsellor. Counselling is available on the NHS, and some hospitals and hospices have counsellors who specialise in cancer. The British Association for Counselling and Psychotherapy has details of qualified counsellors. Read more about psychological therapy services and how to access these on the NHS website.


Your GP can give you medicines such as anti-depressants, to help with anxiety and depression. They can take a few weeks to have an effect. You may not need to take them for a long time, but they may help – for example after you have been diagnosed or during treatment.

Complementary therapies

Some people find that complementary therapies that aim to relax you, such as massage, meditation or mindfulness, help them deal with stress.

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Problems sleeping

Problems sleeping can make fatigue worse.

Problems sleeping can be common in people with cancer.

  • Your sleep may be disturbed by symptoms caused by the cancer or your treatment. These may include pain, discomfort, sickness, needing the toilet, itching or sweating.
  • Feeling anxious or worried can also make sleeping difficult.
  • You may sleep badly if your bedroom is too light, too noisy, too hot or too cold.
  • Some people find that they get a short boost from caffeine (such as coffee and tea), alcohol or sugary foods or drinks. But try to avoid them before you go to bed as they may affect your sleep.
  • For some people, napping during the day and going to bed at different times each evening can also make it harder to sleep at night.
  • Sometimes people with pancreatic cancer may take steroids, for example for pain. Steroids can cause problems sleeping, so it may be best to take them in the morning rather than the evening.

What can help?

Talk to your medical team if you aren’t sleeping well. They can look at whether there is a particular problem and how to manage it.

There are things you can try to help you sleep better at night.

  • Try going to bed at a regular time each evening – following a routine can improve your sleep.
  • Make sure your bedroom is quiet, dark and comfortable.
  • If you are worrying a lot at night, try to do something relaxing before you go to bed. For example, reading, listening to quiet music, a warm bath, or meditation might help. Some people find lavender helps.
  • You might find that writing down your thoughts or worries helps you to stop thinking about them at night.
  • Doing some physical activity during the day may help you sleep better at night.
  • Limit your “screen time” at bedtime, as this may affect your sleep. This includes the time you spend on your phone, tablet, computer or watching the TV. Reading a book or listening to the radio or an audiobook may be a better way to relax.

Having a nap

You may find that napping during the day gives you a bit more energy. But it’s important that it doesn’t disrupt your sleep at night. If it does affect your sleep or you feel worse after a nap, try to avoid napping.

If having a short nap helps, then it is fine. If you are struggling to stay awake, try to limit how long you nap to about 30 minutes, as sleeping too long can affect your natural sleep pattern. You could set an alarm so that you don’t keep sleeping.

An occupational therapist can give you advice about napping during the day and how it might affect your sleeping pattern.

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"It helped to have quiet times during the day, sometimes in a different room to others."

Updated February 2020

To be reviewed February 2022