Pain Assessment Calculator

World Health Organization (WHO) 3-Step Analgesic Ladder

The WHO Analgesic Ladder is the international clinical benchmark for managing acute, chronic, and cancer pain:

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• WHO Step 1: Mild Pain**:

• Medications: Non-opioid analgesics and Non-Steroidal Anti-Inflammatory Drugs (NSAIDs: Ibuprofen, Naproxen, Celecoxib) ± adjuvants.

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• WHO Step 2: Moderate Pain**:

• Medications: Weak opioids (Tramadol, Codeine, Hydrocodone) in fixed-dose combination with Step 1 non-opioids ± adjuvants.

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• WHO Step 3: Severe Pain**:

• Medications: Strong opioids (Morphine, Oxycodone, Fentanyl, Hydromorphone, Buprenorphine) titrated to individual comfort with co-administered non-opioids.

• Neuropathic Pain Exception: Nerve pain (sciatica, post-herpetic neuralgia, diabetic neuropathy) responds poorly to opioids and requires targeted neuromodulators (Pregabalin, Gabapentin, Duloxetine, Tricyclic Antidepressants).

How to Use This Calculator

Enter your Pain Severity Rating (NRS 0 to 10 Scale) (e.g. 6), Pain Type / Etiology — select from Somatic Nociceptive (Aching, localized, throbbing, muscle/bone), Neuropathic (Burning, electric shocks, tingling, sciatica, nerve damage), Visceral (Deep squeezing, poorly localized abdominal/pelvic), Pain Duration & Chronicity — select from Acute Pain (< 3 months / post-injury / post-surgical), Chronic Pain (≥ 3 months / persistent condition), Daily Activity & Functional Impact — select from Mild (Able to perform all work & sleep with minor discomfort), Moderate (Disrupts sleep, concentration, or physical chores), Severe (Incapacitating / largely confined to bed / severe distress), and Clinical Pain Case Benchmark — select from Custom Pain Evaluation, Moderate Post-Surgical (NRS 6/10 / WHO Step 2 Weak Opioid + NSAID), Mild Ankle Sprain (NRS 3/10 / WHO Step 1 Acetaminophen / Ice). Results update instantly — no submit button needed. Use metric or imperial units as labeled. For the most accurate result, measure height and weight in the morning without shoes.

The Formula

Formula Reference: Pain Assessment Calculator

Input variables:

numericPainScaleRating — Pain Severity Rating (NRS 0 to 10 Scale)

painEtiologySelect — Pain Type / Etiology

painChronicitySelect — Pain Duration & Chronicity

functionalImpactSelect — Daily Activity & Functional Impact

Computed outputs:

whoAnalgesicLadderStep — WHO Analgesic Ladder Tier

painSeverityCategory — Clinical Severity Classification

wongBakerFaceEquivalent — Wong-Baker Faces Equivalent

recommendedTherapyClass — Pharmacological & Adjuvant Strategy

Standard: WHO and CDC published clinical reference standards

Worked Example

A patient with burning diabetic neuropathy rating 7/10 pain is correctly triaged away from pure opioids to first-line gabapentinoids and duloxetine, targeting the underlying neuropathic sodium-channel hyperexcitability.

Understanding Your Result

Health calculations based on standard clinical formulas give a population-reference estimate — individual variation exists. Compare your result to the reference ranges provided using validated sources (WHO, CDC, NIH, or specialty clinical guidelines). A single measurement is a starting point; meaningful health trends emerge from tracking the same metric over time under consistent conditions. For values outside reference ranges, consult a qualified healthcare provider before making changes to diet, exercise, or medication.