Chronic pain in older adults

Chronic pain in older adults is pain that persists or recurs for more than 3 months in a person aged 65 or over. It is a symptom, a condition in its own right, or both. It drives disability, falls, depression, sleep loss, social withdrawal and frailty, and it is often undertreated because it is accepted as part of ageing or cannot be reported.

Clinical relevance. Prevalence rises with age and is highest in care homes. Multisite pain is the norm. Pain intensity alone predicts function poorly, so assessment must cover interference with activity, sleep and mood.

Mechanisms. Peripheral and central sensitisation, loss of descending inhibitory control, and reduced physiological reserve all contribute. Pain perception is not meaningfully blunted by age, but reporting is reduced by stoicism, cognitive impairment and aphasia.

Classification by mechanism.

• Nociceptive: somatic (joint, muscle, bone, tendon) or visceral.
• Neuropathic: lesion or disease of the somatosensory system, with burning, shooting or electric pain, allodynia and sensory change in a neuroanatomical distribution.
• Nociplastic: altered pain processing without clear tissue or nerve damage, for example fibromyalgia.
• Mixed: common, for example spinal stenosis with radiculopathy.

Classification by cause. Chronic primary pain has no better explanation by another condition. Chronic secondary pain arises from cancer, surgery, injury, neuropathy, musculoskeletal disease, visceral disease or headache disorders.

Key distinctions. New or worsening pain in an older adult is a change to investigate, not a continuation of the old problem. Opioid induced hyperalgesia, medication overuse and depression can each sustain pain.

History.

• Site (draw a body map), onset, duration, character, severity at rest and with movement, diurnal pattern, aggravating and relieving factors, and night pain.
• Interference with walking, dressing, self care, sleep, mood and social activity, and what the patient most wants to regain.
• Previous injury, surgery, cancer, shingles, diabetes, vascular disease, inflammatory disease and fractures.
• Drug history including every analgesic used, the dose, duration, response and adverse effects, and over the counter products.
• Alcohol, sleep, mood, cognition, fear of movement, expectations, and social and financial stressors.

Assessment tools.

• Numeric rating scale 0 to 10 or a verbal descriptor scale when cognition is intact.
• PAINAD in advanced dementia (0 to 10; 1 to 3 mild, 4 to 6 moderate, 7 to 10 severe), or the Abbey pain scale where used locally. Check behaviour at rest and during movement or care.
• DN4 questionnaire: 4 or more of 10 items suggests neuropathic pain.
• PHQ-2 or the 15 item Geriatric Depression Scale (over 5 suggests depression), cognitive screening, and a validated function measure.

Examination.

• Observe posture, gait, transfers and facial expression during movement.
• Joints: swelling, warmth, crepitus, range of motion, deformity. Spine: tenderness, range, straight leg raise, femoral stretch. Hips and shoulders in all patients with proximal pain.
• Muscles and tendons: tender points, trigger points, proximal power, tendon palpation.
• Neurological: sensory mapping (light touch, pinprick, vibration, allodynia), reflexes, power, gait.
• Vascular: pulses, capillary refill, skin.
• Abdomen, chest and skin (healed herpes zoster scarring), breast, prostate and lymph nodes where cancer is suspected.
• Temporal artery tenderness and scalp tenderness.

Red flags.

• Progressive neurological deficit, saddle anaesthesia, new bladder or bowel dysfunction, or bilateral leg symptoms.
• Spinal pain with fever, intravenous drug use, or recent bacteraemia.
• Unexplained weight loss, night pain, or pain unrelieved by rest, with a history of cancer.
• New headache, jaw claudication, scalp tenderness or visual symptoms.
• Hot swollen joint.
• New severe pain after minor trauma (fracture).
• Rapid escalation of opioid requirement.
• Suicidal thoughts.

Special groups. In dementia, use observation tools and ask carers about changes in behaviour. In kidney impairment, adjust analgesics to Cockcroft-Gault creatinine clearance. In liver disease and low body weight, reduce the paracetamol ceiling.

Musculoskeletal.

• Osteoarthritis (knee, hip, hand, spine), lumbar spinal stenosis, osteoporotic vertebral fracture.
• Rheumatoid arthritis, gout, calcium pyrophosphate deposition disease.
• Polymyalgia rheumatica, giant cell arteritis.
• Fibromyalgia, myofascial pain syndrome, tendinopathy and enthesopathy.
• Paget disease of bone, osteomalacia.

Neuropathic.

• Diabetic peripheral neuropathy, postherpetic neuralgia, trigeminal neuralgia.
• Lumbar and cervical radiculopathy, central post-stroke pain.
• Chemotherapy induced peripheral neuropathy, B12 deficiency neuropathy.
• Complex regional pain syndrome.

Malignant. Bone metastases, multiple myeloma, cancer related and treatment related pain.

Vascular and visceral. Peripheral arterial disease, chronic mesenteric ischaemia, chronic pancreatitis, diverticular disease.

Metabolic, drug and psychological. Hypothyroidism, statin myopathy, aromatase inhibitor arthralgia, depression with somatic pain, opioid induced hyperalgesia.

Step 1. Classify the pain by mechanism, exclude red flag causes, and decide whether the pain is new, changed or long standing.

Step 2. First line tests:

• Full blood count, ESR and CRP, urea, creatinine, eGFR, electrolytes.
• Corrected calcium (over 2.60 mmol/L is hypercalcaemia), alkaline phosphatase, liver tests.
• Glucose and HbA1c, TSH.
• B12: under 200 ng/L is deficient; 200 to 300 ng/L is borderline and needs methylmalonic acid.
• 25 hydroxyvitamin D: under 30 nmol/L is deficient.
• Creatine kinase and urate where indicated.

Step 3. Targeted tests directed by the findings.

• Plain radiographs of painful joints and spine. Radiographic change correlates poorly with symptoms, so avoid imaging for typical osteoarthritis.
• MRI spine for red flags, suspected stenosis, infection or cord compression.
• Serum protein electrophoresis and free light chains for unexplained bone pain, anaemia, raised ESR or hypercalcaemia.
• Bone scan or CT for suspected metastases.
• ESR over 40 mm/h with shoulder and hip girdle pain supports polymyalgia rheumatica. Temporal artery ultrasound or biopsy is needed when giant cell arteritis is suspected.
• Nerve conduction studies for neuropathy not explained by simple causes. Ankle brachial index for suspected arterial disease.
• Joint aspiration with crystal analysis and culture for monoarthritis.

Limitations. ESR and CRP rise with age and inflammation. Imaging shows incidental degeneration in most older adults. Vitamin D levels rarely explain pain alone.

Principles. Set shared functional goals, use the lowest effective dose, change one drug at a time, review benefit and harm at each step, and stop treatments that do not help. Medicines are an adjunct to activity, not a substitute.

Non-drug treatment (first line for most patients).

• Exercise: supervised strengthening and aerobic programme, two to three sessions weekly, with graded increase.
• Weight reduction for knee and hip osteoarthritis, heat, walking aids, footwear and joint protection.
• Cognitive behavioural approaches, pacing, sleep measures and treatment of depression.
• Transcutaneous nerve stimulation and acupuncture have limited evidence. Spinal manipulation carries risk in older adults with osteoporosis.

Paracetamol.

• 1 g orally every 6 hours regularly. Maximum 4 g daily (3 g daily if weight under 50 kg, malnutrition, chronic alcohol excess or liver disease).
• Review at 2 to 4 weeks and continue only if useful. Monitor liver tests with prolonged use.
• Reduce the dose or lengthen the interval in kidney impairment with CrCl under 30 mL/min.

Topical therapy. Diclofenac 1% gel:

• 2 g to upper limb joints or 4 g to lower limb joints applied four times daily to intact skin.
• Maximum 8 g daily to any upper limb joint, 16 g daily to any lower limb joint and 32 g daily in total.
• Use for up to 12 weeks then review. Avoid broken skin, eyes and occlusive dressings.
• Systemic absorption is low but not zero. Avoid in aspirin sensitive asthma and use with caution in CrCl under 30 mL/min.

Lidocaine 5% medicated plaster for localised neuropathic pain: up to 3 plasters on intact skin for 12 hours, then 12 hours off, in each 24 hours. Maximum 3 plasters. Stop if no benefit at 4 weeks. Use caution in severe liver impairment.

Oral NSAID. Avoid where possible. If used for a flare:

• Naproxen 250 mg orally twice daily, increased to 500 mg twice daily if needed. Maximum 1000 mg daily. Shortest course, usually under 2 weeks.
• Add omeprazole 20 mg orally once daily.
• Monitor blood pressure, creatinine, haemoglobin and heart failure signs.
• Avoid in eGFR under 30 mL/min, heart failure, previous gastrointestinal bleeding, anticoagulant use, and recent myocardial infarction or stroke.

Neuropathic pain.

• Gabapentin: start 100 mg orally at night. Increase every 3 to 7 days in steps of 100 to 300 mg daily toward 300 mg three times daily. Maximum 3600 mg daily in normal kidney function, with most older adults needing much less. Review at 4 to 8 weeks. Monitor for sedation, dizziness, oedema, falls and respiratory depression, especially with opioids. Withdraw over at least 1 week.
• Gabapentin renal dosing: for CrCl 30 to 59 mL/min give 400 to 1400 mg daily in two divided doses, for CrCl 15 to 29 mL/min give 200 to 700 mg once daily, and for CrCl under 15 mL/min give 100 to 300 mg once daily.
• Pregabalin: start 25 mg orally once or twice daily, increase after 3 to 7 days to 75 mg twice daily, then up to 150 mg twice daily if needed. Maximum 600 mg daily. Review at 4 weeks. Same monitoring as gabapentin, with misuse potential.
• Pregabalin renal dosing: for CrCl 30 to 60 mL/min the daily range is 75 to 300 mg in two or three doses, for CrCl 15 to 30 mL/min 25 to 150 mg once or twice daily, and for CrCl under 15 mL/min 25 to 75 mg once daily.
• Duloxetine: 30 mg orally once daily for 1 week, then 60 mg once daily. Maximum 120 mg daily, with little added benefit over 60 mg. Assess at 4 weeks. Monitor sodium (SIADH), blood pressure, falls, bleeding with anticoagulants, and serotonin toxicity. Avoid if CrCl under 30 mL/min or significant liver disease. Taper over 2 to 4 weeks.
• Nortriptyline as a second line option: 10 mg orally at night, increase by 10 mg weekly to 25 to 50 mg at night. Maximum 75 mg daily in older adults. ECG before starting. Avoid in conduction block, recent myocardial infarction, narrow angle glaucoma, urinary retention and dementia. Monitor orthostatic blood pressure, sedation and constipation.

Opioids (time limited course only after non-opioid measures fail).

• Tramadol: 50 mg orally every 6 to 8 hours as needed. Maximum 300 mg daily over age 75 (400 mg daily in younger patients). Review at 2 to 4 weeks. Monitor sedation, nausea, constipation, sodium, glucose and seizure risk. Avoid in epilepsy and with SSRIs, SNRIs or monoamine oxidase inhibitors. For CrCl under 30 mL/min extend the interval to 12 hours with a maximum 200 mg daily.
• Buprenorphine 7 day patch: 5 micrograms/hour applied to clean skin and changed every 7 days. Increase not sooner than 3 days after starting. Maximum 20 micrograms/hour. Monitor sedation, respiratory rate and application site. Avoid heat on the patch. No dose adjustment in kidney impairment; it is the preferred option when eGFR is under 30 mL/min.
• Morphine immediate release: 2.5 mg orally every 4 hours as needed in opioid naive older adults. Reassess benefit before exceeding 50 mg oral morphine equivalent daily and avoid more than 90 mg. Avoid in eGFR under 30 mL/min because of active metabolites.
• Prescribe a laxative with every opioid: macrogol 1 sachet daily or senna 7.5 to 15 mg orally at night, adjusted to bowel function. Stop the opioid if function and pain do not improve.

Interventions. Intra-articular corticosteroid for knee and shoulder osteoarthritis flares (for example methylprednisolone 40 mg injected once, repeated no more often than every 3 months; monitor glucose in diabetes). Facet joint and epidural injections, vertebroplasty and nerve ablation are specialist options for selected patients.

Monitoring. Review at 2 to 4 weeks after each change, then every 3 to 6 months. Track function, sleep, mood, falls, bowel habit, cognition and adverse effects. Check sodium after starting duloxetine, creatinine with gabapentinoids and NSAIDs.

Referral and escalation. Pain service for refractory pain, complex neuropathic pain, high opioid doses or suspected opioid misuse. Rheumatology for inflammatory disease. Orthopaedics for joint replacement. Oncology or palliative care for cancer pain. Physiotherapy, occupational therapy and psychology for most patients. Urgent spinal assessment for cord compression or cauda equina features.

Admission criteria. Suspected cord compression, spinal infection, fracture, acute severe pain with a serious cause, uncontrolled pain, delirium with opioids, or a high suicide risk.

Discharge and safety netting. Discharge with a written plan, a medicine list showing the maximum daily doses, a laxative plan and a review date. Patients and carers are told to return for new weakness, numbness, bladder or bowel change, fever, chest pain, sedation or confusion.