Cancer pain: causes, types and how it is managed

Cancer Research UK explains that when any part of the body is damaged, the nervous system sends a message along nerves to the brain and you feel pain, and that pain is usually a sign that something is wrong. Most cancer pain is caused by the tumour pressing on bones, nerves or other organs. A very small tumour pressing on a nerve or the spinal cord can be extremely painful, while a large one elsewhere may cause none, so how much pain you have is not necessarily linked to how fast the cancer is growing.

Pain can also come from treatment. Cancer Research UK gives examples: some chemotherapy drugs cause numbness and tingling in the hands and feet, radiotherapy can cause skin redness and irritation, some immunotherapy treatments can cause joint swelling, and some hormone therapies cause joint and muscle pain. Surgery can cause acute pain that settles as the wound heals, and some people have longer-term nerve pain afterwards.

Cancer Research UK stresses that it is very important for the doctor to find out the type and cause of the pain, because different types need different treatment. It describes the following, and notes that pain may also be acute (short-lived, such as after an operation) or chronic (continuing long after the injury or treatment).

Before pain can be managed the team needs a proper assessment. Cancer Research UK says this means questions about where the pain is, what it feels like, how long it lasts, what eases or worsens it, how strong it is on a scale of 0 to 10, what medicines you take and whether it stops you doing everyday things. They may also ask about eating, bowels and passing urine, and may examine you or arrange X-rays or blood tests.

Pain scales and a pain diary are useful. Cancer Research UK suggests noting where it is, what it feels like, what relieves it, how often it comes, and whether it comes on suddenly or gradually, along with what you were doing and what medicine you took. If numbers are hard, words such as mild, moderate or severe will do. Assessment is not one-off: it is repeated to check how well treatment is working. Family or friends can help describe pain if you do not feel up to it.

Cancer Research UK describes many ways of treating cancer pain, with different professionals able to help. The treatment depends on what is causing the pain.

• Painkillers: opioids (morphine-type drugs), non-opioids and other drugs such as steroids or antidepressants, which may be used for nerve pain.

• Cancer treatments that reduce pain: treatments used against the cancer can shrink it and reduce pressure on nerves and surrounding tissues.

• Nerve blocks: a procedure that kills or deadens a nerve to stop it causing pain, for pain that is difficult to treat.

• Treatments to strengthen painful bones where cancer has spread to them.

• Things you can do yourself, including complementary therapies and a TENS machine, as part of an individual plan.

It is important to take painkillers regularly as prescribed. Cancer Research UK says pain that is not well controlled can develop into chronic pain, and that trying to put up with it can cause nerve changes that make it harder to control later. It also points out that some people have breakthrough pain, times when regular medicines do not control the pain all the time, and says to tell the doctor or nurse if you are taking regular painkillers and still get such episodes.

Fear of addiction stops some people asking for help. Cancer Research UK says addiction is very rare in people taking painkillers for cancer pain. Cancer Research UK adds that some painkillers can have side effects, and that you should tell your doctor or specialist nurse about any so they can help you through them.

Pain that is new, worse, or not controlled by your current plan should be raised with your cancer team, specialist nurse or GP promptly rather than waiting for the next appointment. Cancer Research UK says the first step is always to tell your doctor or specialist nurse that you have pain. If pain is sudden and severe, or comes with other worrying symptoms, use your emergency contact arrangements from your cancer team, NHS 111, or 999 in an emergency.

Pain affects people physically and emotionally, and what is painful for one person may not be for another. Cancer Research UK says other factors can influence how pain feels, including fear, anxiety, depression and lack of sleep. It is normal to feel upset or frightened, and support is available, for example through your care team, specialist palliative care or symptom control teams, and charities such as Pain Concern and Macmillan Cancer Support, which Cancer Research UK lists.

Cancer pain is managed by your oncology team, GP, community nurses and, where needed, specialist palliative care or pain teams on the NHS. Some people also see a private pain specialist, which can be quicker to arrange. The medicines and techniques are broadly the same; make sure any private clinician is in touch with your cancer team so that opioids and other treatments are not duplicated or interacting.