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Complex or Persistent Pain Care Pathway Overview

Pain is an almost universal experience.Everyday pain e.g. headaches, pain after exercise, minor injury pain, usually passes quickly and doesn't need treatment. It is normal for tiredness, anxiety and low mood to make all type of pain feel more intense.

Pain is usually classified depending on duration of symptoms. Acute pain is short term pain usually relating to some sort of injury including operation, fracture or infection. Chronic pain is longer lasting, usually more than three months and includes low back pain and arthritis. Sometimes chronic pain can develop from an acute pain that persists. Emergence of chronic pain following an acute pain presentation should be considered if pain persists beyond the expected time of healing of the acute injury. Pain from nerve damage e.g. diabetes, shingles, multiple sclerosis, is described as neuropathic pain which is a type of chronic pain. (The term nociceptive pain implies pain associated with a specific definable injury process that is non-neuropathic). Visceral pain is pain arising from pelvic, abdominal or thoracic organs for example prostatic pain syndrome, loin pain haematuria syndrome and endometriosis. This type of pain may have neuropathic characteristics but may be particularly complex and always need a detailed assessment.

Pain rarely fits into a discrete diagnostic catgeory. Symptoms may fall into more than one category.

To support management planning it is more helpful to think about:

  • Acute pain
  • Persistent pain associated with obvious tissue injury
    • Neuropathic
    • Not neuropathic
  • Complex pain (see below)

Both acute and chronic pain can range from mild to severe. Intensity of acute pain is largely (but not completely) related to the degree of tissue injury: a big injury or operation hurts more than a small one. There is no similar relalationship for chronic pain. The amount of tissue damage is a small contributor to pain intensity. Bigger contributors are anxiety, distress, depression and concern about causes of pain. Also, unpleasant thoughts, feelings and memories (if related to pain) can influence pain severity. N.B This is not a reporting bias: these influences actually influence pain perception directly.

Acute pain is usually self-limiting and symptoms should resolve within days or weeks. Treatment needs to be given while healing occurs. Acute pain usually responds well to analgesic medicines. Severe acute pain e.g. following minor injury or surgery will usually need to be treated with strong opioids but the dose needs to be reduced as the patient recovers.

Paint that persists (chronic pain) has many effects including lack of mobility, low mood, poor sleep, irritability and interruption of work and social activities. Persistent pain is difficult to treat with most treatments helping less than a third of patients. Different treatments work for different patients. Medicines generally and opioids in particular are often not very effective for chronic pain but some medicines are worth trying for neuropathic pain. If a treatment is helpful it doesn't usually take away pain completely but can reduce intensity enough to help improve day to day function and support the patient in self-managing symptoms. Anxiety, depression, post-traumatic stress disorder, and previous emotional trauma or other mental health diagnoses, will make the pain feel worse and make it more difficult to treat.

Classifying pain according to duration of symptoms is rather artificial but may be helpful in defining populations for research. Some acute pains may go on for a long time e.g. extensive burns needing dressing. Sometimes patients will present with a short history of severe pain associated with significant distress and worsened by low mood, anxiety and stressful life circumstances. This sort of pain is likely to be similar in clinical course and prognosis to long-term pain. In clinical practice it might be more helpful to think about pain as acute, relating to obvious tissue injury, and complex or persistent pain, where tissue injury is a relatively small contributor to the presentation and where medical interventions including medicines are less likely to be helpful.

NB. It can be helpful to explain to patients that the term 'complex' does not infer the presence or absence of painful pathological processes. Simply it acknowledges that emotional influences affect the physical experience of pain in a direct way. It is important to explain to patients that the pain is not 'in his/her head': the experience of pain is very real but is unlikely to respond to analgesic medicines or medical interventions. Addressing co-occurring emotional problems (depression, anxiety, post traumatic stress disorder (PTSD) etc.) and the consequences of persistent pain (poor mobility, disrupted sleep) are more likely to be helpful in symptoms management and the general focus will be supporting the patient to achieve a better quality of life with their pain.

Please click the relevant flowchart box to be taken directly to textual information.


Red Flags for Complexity
N.B. Pain is a very common symptom and clinical judgement should identify patients who have pain as a symptom of treatable underlying pathology. Red flags for serious spinal pathology can be found here. (to be linked)
Red, yellow, orange, blue and black flags have been described in relation to persistent pain: these are unlikely to aid decision making in primary care. An experienced clinician will recognise a complex pain presentation. 'Red Flags' for complexity may include:
  • Multiple physical complaints
  • Complex emotional history
  • Current psychosocial difficulties
  • Diagnostic tests to date unhelpful
  • Pain described as severe and disabling
  • Requests for more investigations, secondary care opinions
  • High levels of distress in patient
  • High levels of doctor distress
  • Patient and doctor unsatisfied with therapeutic interactions
  • Doctor feels frustrated and powerless to help patient

It is important for the patient that complex pain is recognised: this avoids direct harms from treatments unlikely to help and allows prompt agreement of a patient-centred management plan.

Practice Point

Please see the "Urgent Care: general" section on G-care for SWAST's guidance on Requesting Ambulance Transport (999 or Urgent).


Patient presents with pain as primary reason for seeking help. May be:

  • Acute (short term) pain related to obvious injury or
  • Long-term pain: may be
    • Pain from an injury that persists after healing is expected to have occurred
    • Persistent pain with spontaneous onset

All pain is likely to be associated with some impairment of day to day function including reduced mobility, poor sleep, difficulty in working and low mood.

Differential Diagnosis

Pain is a common symptom of many medical conditions and may appear as a complication of medical or surgical treatment. A full medical assessment is always needed to exclude treatable pathological processes.

Common mental health diagnoses particularly depression and anxiety often co-occur with pain and can precede onset of pain or develop subsequently. These need to be identified and managed in accordance with local protocols. If untreated, these conditions can be a barrier to effective pain management.

It is well documented that previous traumatic experiences including physical or sexual abuse, neglect and post-traumatic stress disorder (PTSD) are prevalent in populations with persistent pain and can complicate pain management. Screening for previous trauma is particularly important for patients with severe pain and distress and pain associated with symptoms in other systems and in patients who have disabling pain despite high doses of pain medicines. This allows additional emotional needs to be identified and support offered as part of the pain management plan.

Initial Primary Care Assessment

Exclude treatable causes of disease related pain.

A detailed pain assessment may be impractical within a GP consultation. The following can be useful in deciding next best steps. Much of this information will be known already: consider how this may impact on the experiences of pain.

  • Type of pain (continous or intermittent)
  • Quality of pain (e.g. stabbing, burning or shooting pain or skin hypersensitivty may suggest neuropathic pain)
  • Consequences of the pain (e.g. poor sleep, mobility impairment)
  • Response to medicines including over the counter and illicit drugs
  • Previous medical and surgical history
  • Emotional history including childhood adverse events or trauma in adulthood
  • Current mood (screen for depression)
  • Substance misuse history including alcohol and tobacco
  • Family/social/vocational/forensic history
  • What does the patient think is the cause of the pain?
  • Does the patient have any specific worries about the cause for the pain?

Diagnostic tests should be ordered in accordance with clinical judgement and locally agreed protocols. Explain to the patient that diagnostic tests are often normal in complex pain presentations.

Initial Management

Explain to patient:

  • That persistent pain may be difficult to treat and that treatments, particularly medicines, may cause more harm than good.
  • Medicines don't work for everyone and no treatment gets rid of pain
  • Aims of treatment are to improve quality of life with pain

Discuss (where appropriate) importance of general measures e.g. weight loss (lower limb arthritis), activity, sleep hygiene, relaxation.

Manage co-morbid depression and anxiety in accordance with local protocols.

  • If medicines are used this should be a short term trial only to gauge early indications of helpfulness.
  • Agree goals of management other then reduced pain.
  • Medicines management for acute and complex or persistent pain can be found here.
  • Review within two weeks to assess whether goals of therapy have been achieved.
  • If a patient has no benefit from a pain medicine within two weeks of achieving a therapeutic dose, the drug should be tapered and stopped. Please see here for tapering schedules page 35-35 of the Joint Countywide Formulary)

NB. Manage yourself! Complex pain is difficult to treat and GPs describe pain consultations as some of the most challenging in clinical practice. Recognise and manage your own emotions and discuss cases with colleagues. Failure to relieve pain symptoms is the norm in complex presentations and is not a sign of incompetence or lack of effort.

When to Refer

Consider referral to secondary care for patients with persistent disabling symptoms despite general wellbeing advice (including activity, sleep hygiene, relaxation) and optimisation of pain medicines as per the pain formulary.

Explain that:

  • Persistent pain is hard to treat and many people have persistent symptoms despite specialist input
  • Referral for more detailed assessment to exclude treatable pathology and improve understanding of the factors influencing the experience of pain
  • Treatments offered through pain services aim to support the patient to live well with pain
Secondary Care Management

Referral to secondary care pain services provides support for the ongoing pain management plan including:

  • A full reassessment of the patient and their pain including exploration of emotional co-morbidities and eliciting the patients' concerns and worries about their pain and their expectations about how healthcare services can support their management.
  • Screening/diagnostics for pathology that may be amenable to definitive medical management.
  • Confirmation of a formulation of complex or persistent pain.
  • Validating the patient's experience of pain and explanation of complex pain.
  • Optimising pain medicines and planning tapering schemes for medicines that are poorly effective.
  • Discussing adjuncts to self-management.
  • Referral to pain self-management programme

Pain self-management programme:

  • Aged 18 years and over
  • Chronic Pain for 6 months or more, arising from certain diagnoses including musculoskeletal conditions
  • Distressed, and/or disabled, or struggling to maintain daily function/work
  • Appropriately investigated
  • May still be waiting for, or having medical treatment for this problem e.g. injections/acupuncture etc., but not surgery
  • Patient is open to idea of learning self-management/lifestyle changes, although it is NORMAL for them to be sceptical

  • Are awaiting further investigation, or possible surgery for this condition
  • Have red flags for structural pathology which have not been fully investigated
  • Have active inflammatory conditions or those awaiting investigations to rule this out
  • Have active cancer, or those awaiting investigations to rule this out
  • Are certain that they do not want to find out more about self-management/lifestyle change approaches or
  • Are adamant that they need magnetic resonance imaging (MRI)/further investigation/further consultant assessment. Pain clinic referral may well be helpful to enable these patients to become more accepting and therefore more ready for pain management
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