Physical side effects of advanced cancer

Advanced cancer can cause troubling physical problems. These usually depend on the type of cancer you have and where it has spread.

Be sure to talk to your healthcare team about any of these symptoms. They can’t always be completely controlled, but there is usually something that can be done to give you some comfort and relief.


Constipation is common in people with advanced cancer. It can be caused by pain-relieving drugs like opioids, eating and drinking less or being less active.

Find out more about constipation.


You may not take in enough liquid if you have advanced cancer, either because you don’t feel like drinking or you can’t swallow. This leads to a harmful loss of fluids in the body (dehydration).

The healthcare team may treat dehydration in someone with advanced cancer by giving extra fluids through a needle placed just under the skin (hypodermoclysis) or through a vein (intravenous).

Giving extra fluids

Many family members want their loved ones to have extra fluids if they are dehydrated. They are concerned that being thirsty will make their loved one suffer and that the person will die sooner.

There are no standard guidelines about giving extra fluids to someone with advanced cancer, so it’s important to talk to the healthcare team. Giving extra fluids when someone is palliative depends on many factors, including any wishes that the person with cancer stated about their care, any benefits and risks, and whether it will improve or worsen quality of life and symptoms.

Difficulty breathing

Some people with advanced cancer may have trouble breathing or feel short of breath. This can be very scary. Shortness of breath can be caused by the cancer or by a lung infection (pneumonia). Other causes are a pleural effusion or a pericardial effusion.

Find out more about difficulty breathing.


Fatigue is very common in people with advanced cancer. You may find that you have less energy and get tired easily. You may feel drowsy and less alert. Fatigue can significantly affect your mood, appetite and overall quality of life.

Find out more about fatigue.

Loss of appetite and weight loss

Many people with advanced cancer have a loss of appetite. It occurs because cancer or its treatments can affect the way food tastes or you don’t feel like eating. Closer to the end of life, the body’s systems normally slow down and you may not be able to digest food and water.

If you don’t eat enough, you can lose weight. Weight loss is one of the most common side effects of advanced cancer.

Advanced cancer causes a significant loss of muscle mass or muscle wasting (cachexia), which makes someone extremely thin. Friends and family find it very upsetting to watch a loved one lose weight, especially when the person simply doesn’t want to eat. It may help to understand that if your loved one has a significant loss of appetite or has lost a lot of weight, eating more will not increase their energy or make their life longer.

Find out more about loss of appetite.

Mouth problems

Mouth problems with advanced cancer include a dry mouth or a sore mouth and throat. These problems can be caused by breathing through the mouth (rather than the nose), drinking less and some types of treatment. If the immune system is weakened because of treatment or advanced disease, people are at risk of developing mouth or throat infections.

Find out more about a dry mouth or sore mouth and throat.

Nausea and vomiting

Many people with advanced cancer can have problems with chronic nausea and vomiting. Nausea and vomiting may be caused by pain-relieving drugs, constipation, cancer growth, blockage of the bowel or because digestion slows down. Nausea is often worse when you are tired or anxious.

Find out more about nausea and vomiting.


You’re not alone if pain is one of your biggest fears. People with advanced cancer have different causes or types of pain, such as bone and nerve pain. It’s hard to avoid pain entirely with advanced cancer, but most pain can be managed. When your pain is well controlled, your quality of life is better.

Pain may be less of a problem as death approaches because the person is not moving around as much. Drugs to treat pain can be used even if a person is unconscious. These drugs help keep the person with cancer comfortable. Signs of pain in someone who is unconscious are frowning, grimacing or tension in the skin in the forehead. Groaning and moaning may also be signs of pain, but it’s common for people who are dying to make these noises. Sudden, severe pain that can’t be treated is rare in the last hours before death.

Find out more about pain.

Pressure sores

Pressure sores can develop if someone stays in one position too long. People who have lost a lot of weight are at a higher risk of getting pressure sores. They are most often found on areas where the joints are close to the skin (hips, ankles, heels and elbows). If left too long, these sores can break open or become infected.

Following these tips may help prevent or relieve pressure sores:

  • turning frequently in bed
  • using pillows under joints to help relieve pressure
  • protecting pressure areas with foam pads, sheepskins or special mattresses
  • making sure that sheets and bedding are not wet, wrinkled or irritating to the skin
  • keeping the skin clean and dry and checking skin daily for any changes

Report any changes to the skin, especially red or broken skin, to the healthcare team.

Find out more about skin problems.

Skin problems

People with advanced cancer may have skin problems, such as dryness, itching or redness over the joints. Skin may become thin and very fragile. These problems can be caused by drinking less fluid, eating less and weight loss.

Sleep problems

Physical discomfort, medicines, stress, emotional upset or fear of not waking up can change your normal sleep patterns. Lack of sleep and feeling tired can make weakness and other symptoms worse. Talk to your doctor or another member of your healthcare team. They can try to find the cause of your sleep problems and change treatments as needed. Medicines may be prescribed if sleep problems continue.

Find out more about sleep problems.

Expert review and references

  • When death is near. Canadian Virtual Hospice Team. Canadian Virtual Hospice. Canadian Virtual Hospice Executive Committee; 2010.
  • National Cancer Institute. Fact Sheet: End-of-Life Care for People Who Have Cancer. Bethesda, MD: National Cancer Institute; 2012.
  • Paice JA . Care during the final days of life. Yarbro, CH, Wujcki D, & Holmes Gobel B. (eds.). Cancer Nursing: Principles and Practice. 7th ed. Sudbury, MA: Jones and Bartlett; 2011: 75: pp. 1829-1842.
  • Rousseau P . Management of symptoms in the actively dying patient. Berger, A. M., Shuster, J. L. Jr., & Von Roenn, J. H., (eds.). Principles and Practice of Palliative Care and Supportive Oncology. 2nd ed. Philadelphia: Lippincott Williams & Wilkins; 2007: 57: pp. 623-632.

Medical disclaimer

The information that the Canadian Cancer Society provides does not replace your relationship with your doctor. The information is for your general use, so be sure to talk to a qualified healthcare professional before making medical decisions or if you have questions about your health.

We do our best to make sure that the information we provide is accurate and reliable but cannot guarantee that it is error-free or complete.

The Canadian Cancer Society is not responsible for the quality of the information or services provided by other organizations and mentioned on, nor do we endorse any service, product, treatment or therapy.

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