• Discuss pain with the person directly if possible. The person, if competent and able to communicate, is the most reliable source of information about their pain. If it is not possible to ask them (because of cognitive impairment or communication deficits, for example), the family or healthcare professionals may be able to help with the assessment, bearing in mind that family members may overestimate, and healthcare professionals underestimate, the person's pain.
• Assess each pain a person has, bearing in mind that there may be more than one. Seek specialist advice if assessment is difficult because of complex or multiple pains.
• Assess pain regularly, particularly if it is not adequately controlled.
• Review the medical history and medical records to determine the known site and extent of the cancer. Pain occurring distant from the previously known sites of cancer may indicate either a non-malignant cause or secondary spread of the cancer.
• Assess the influence of psychological, social, and spiritual factors on the person's experience of pain.

In depth

• Use a validated structured pain assessment tool, for example:
• Numerical rating scale — mark on a scale of 0 (no pain) to 10 (worst possible pain) how strong the pain is.
• Visual analogue scale — mark on a 10-cm line (with 'no pain' at one end and 'worst possible pain' at the other end) how strong the pain is.
• The score can be correlated to the severity of the pain:
• Mild pain: less than 3 out of 10 on a visual analogue scale or numerical rating scale.
• Mild to moderate pain: 3–6 out of 10 on a visual analogue scale or numerical rating scale.
• Severe pain: more than 6 out of 10 on a visual analogue scale or numerical rating scale.
• Differentiate between the person's usual level of pain, breakthrough pain, incident pain, and 'end of dose' failure of regular around-the-clock analgesia. End of dose failure usually occurs at the same time each day, usually just before the next dose is due.

In depth

• Enquire about:
• Site and number of pains.
• Radiation.
• Quality.
• Timing (onset, duration, breakthrough or incident pain).
• Exacerbating and relieving factors.
• Associated symptoms and signs.
• The person's thoughts about the likely cause.

In depth

• Assess the effect of the pain on activities of daily living, mood, and sleep.
• Identify factors contributing to the person's distress (for example, anxiety, depression, other physical symptoms, family or carer distress).

In depth

• Enquire about:
• Response to previous analgesia (including allergies or sensitivities).
• Use of over-the-counter or complementary therapies and other prescribed medication.
• The person's treatment preferences (for example, preferred route of administration, a wish not to experience sedative effects from medication so that they can remain mobile).
• Concerns of the person and their family (for example, regarding opioid use).

In depth

• Examine the person, if appropriate. A full examination is rarely appropriate in people who are very unwell and in the last stages of life.
• Look particularly for specific points of tenderness (which may indicate the site of origin of the pain) and signs of neurological deficit which may suggest spinal cord compression.

In depth

• Consider investigations that are appropriate to the person's condition.
• Limit investigations to those likely to significantly affect treatment decisions.
• If the person is near the end of life, investigations are rarely indicated. They may be performed if a reversible condition may be the cause of their deterioration, or if the person has acute (potentially reversible) deterioration.
• If investigations are appropriate, ensure that the person's pain is adequately treated before they undergo diagnostic procedures. For more information on how to prescribe for incident pain (such as pain on movement), see Management of breakthrough pain.

In depth