Assessing Acute Pain and Chronic Pain

Pain assessment is a core clinical skill and one of the most common reasons patients seek medical care. Understanding the difference between acute pain and chronic pain, and assessing each correctly, is essential for safe treatment, improved function, and patient trust.

This guide explains how to assess pain systematically, using evidence-based tools and a multidisciplinary approach.

What Is Pain?

According to the International Association for the Study of Pain (IASP), pain is:

“An unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.”

Pain is not only physical. It involves:

• Sensory perception
• Emotional response
• Cognitive interpretation

Pain can exist even when imaging and laboratory tests are normal. This is a medical reality, not a diagnostic failure.

Acute Pain vs Chronic Pain

Acute Pain

Acute pain features include:

• It occurs suddenly
• It’s usually linked to injury, surgery, or illness
• It has a protective biological function
• It resolves as healing occurs

Chronic Pain

Chronic pain is defined as:

• Pain lasting more than 3–6 months
• Pain persisting beyond normal tissue healing
• Pain that recurs over months or years

Chronic non-cancer pain:

• Affects ~100 million Americans
• Accounts for 5%–33% of primary care visits
• Is the leading cause of long-term disability

Over 40% of patients report inadequate pain control, highlighting the need for better assessment and follow-up.

Why Accurate Pain Assessment Matters

Pain is multifactorial. It is influenced by:

• Tissue damage
• Nervous system changes
• Mental health
• Social and cultural factors
• Prior trauma

A measurement-based, patient-centered approach improves outcomes and reduces unsafe medication use.

Listening to the patient’s pain story is not optional—it is diagnostic.

How to Take a Complete Pain History

1. Onset and Pattern

Ask:

• When did the pain start?
• Was it related to injury or illness?
• Is it constant or intermittent?
• Does it change with time of day or movement?

2. Pain Characteristics

Assess:

• Location (ask the patient to point)
• Quality (sharp, dull, burning, electric)
• Radiation or pattern
• Aggravating and relieving factors

3. Previous Treatments

Review:

• Medications (past and current)
• Physical therapy
• Injections or procedures
• Complementary therapies

A thorough medication history prevents dangerous interactions.

4. Comorbid Conditions

Conditions that strongly affect pain perception include:

• Arthritis
• Diabetes
• HIV/AIDS
• Sickle cell disease
• Depression and anxiety
• Substance use disorders

Ignoring comorbidities leads to treatment failure.

5. Functional Impact

Ask how pain affects:

• Daily activities
• Sleep quality
• Mood and concentration
• Work and productivity
• Sexual activity

Pain that limits function is clinically significant—regardless of imaging results.

Assessing Pain Severity: Standard Pain Scales

Consistent measurement is essential.

Common Pain Severity Scales

• Numeric Rating Scale (0–10)
• Visual Analog Scale (VAS)
• Wong-Baker FACES Pain Rating Scale

The Wong-Baker FACES® scale is especially useful for:

• Children
• Patients with language barriers
• Cognitive impairment

Multidimensional Pain Tools

• Brief Pain Inventory
• McGill Pain Questionnaire

These tools assess both pain intensity and its impact on daily life.

See Also: LANSS Pain Scale

Health Disparities in Pain Assessment

Research shows clear disparities in pain treatment:

• Lower use of analgesics in minority populations
• Unequal management of cancer, postoperative, and low back pain

Contributing factors include:

• Implicit clinician bias
• Language barriers
• Communication failures

Standardized pain assessment tools reduce bias and improve equity in care.

Types of Pain

Nociceptive Pain

• Caused by tissue injury or inflammation
• Nervous system intact
• Examples: arthritis, spinal stenosis
• Can be acute or chronic

Neuropathic Pain

• Caused by nerve injury or disease
• Burning, shooting, or electric pain
• May persist after healing

Central Sensitization Pain

• Amplified pain processing in the central nervous system
• Lower pain threshold
• Example: fibromyalgia

Psychogenic Pain

• Strongly influenced by mental health, coping style, and social factors

Idiopathic Pain

• Pain without identifiable cause
• Still real and clinically relevant

Managing Chronic Pain: Measurement-Based Care

Chronic pain management requires structured monitoring.

Key Steps in Chronic Pain Assessment

1. Measure pain intensity and interference with daily life
2. Screen for depression, anxiety, and PTSD
3. Evaluate sleep quality
4. Assess risk of substance use disorders
5. Monitor opioid dose and equivalents

This approach improves safety and treatment precision.

Opioids and Chronic Pain: A Cautionary Note

Opioid prescriptions have increased dramatically over recent decades. While opioids have a role in selected cases, risks rise sharply with:

• High daily doses
• Older age
• Depression or substance use
• Concurrent benzodiazepines

Effective pain management prioritizes:

• Non-opioid therapies
• Physical rehabilitation
• Behavioral interventions
• Careful monitoring

Poor pain assessment directly leads to poor—and sometimes fatal—treatment decisions.

Key Takeaways

• Pain assessment must be systematic and patient-centered
• Chronic and Acute pain require different clinical strategies
• Functional impact matters as much as pain intensity
• Measurement-based care improves outcomes and safety

Pain is real—even when tests are normal. Assess it seriously, or expect treatment failure.

References & More

1. Chou R, Wagner J, Ahmed AY, et al. Treatments for Acute Pain: A Systematic Review [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2020 Dec. (Comparative Effectiveness Review, No. 240.) Introduction. Available from: Pubmed
2. National Academies of Sciences, Engineering, and Medicine; Health and Medicine Division; Board on Health Care Services; Committee on Evidence-Based Clinical Practice Guidelines for Prescribing Opioids for Acute Pain. Framing Opioid Prescribing Guidelines for Acute Pain: Developing the Evidence. Washington (DC): National Academies Press (US); 2019 Dec 19. 2, Managing Acute Pain. Available from: Pubmed
3. Carr DB, Goudas LC. Acute pain. Lancet. 1999 Jun 12;353(9169):2051-8. doi: 10.1016/S0140-6736(99)03313-9. PMID: 10376632. Pubmed
4. Bickley, L. S., Szilagyi, P. G., Hoffman, R. M., & Soriano, R. P. (2021). Bates’ guide to physical examination and history taking, 12e.